134 ideas
| 11283 | There is pure deductive reasoning, and explanatory demonstration reasoning [Aristotle, by Politis] |
| Full Idea: Aristotle distinguishes between deductive reasoning (sullogismos) and demonstration (apodeixis). All demonstration is deductive reasoning, but not all deductive reasoning is demonstration. | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE], Bk I.2) by Vassilis Politis - Aristotle and the Metaphysics 5.3 | |
| A reaction: This sounds not far off the distinction between single-turnstile (formal proof) and double-turnstile (semantic consequence). Politis says, though, that the key point is the demonstration is explanatory. |
| 1672 | Maybe everything could be demonstrated, if demonstration can be reciprocal or circular [Aristotle] |
| Full Idea: Some optimists think understanding arises only through demonstration, but say there could be demonstration of everything, for it is possible to demonstrate in a circle or reciprocally. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 72b16) | |
| A reaction: I'm an optimist in this sense, though what is being described would probably best be called 'large-scale coherence'. Two reciprocal arguments look bad, but a hundred look good. |
| 3807 | Reason is and ought to be the slave of the passions [Hume] |
| Full Idea: Reason is and ought to be the slave of the passions, and can never pretend to any other office than to serve and obey them. | |
| From: David Hume (Treatise of Human Nature [1739], II.III.3) |
| 1684 | Two falsehoods can be contrary to one another [Aristotle] |
| Full Idea: There are falsehoods which are contrary to one another and cannot be the case together e.g. that a man is a horse or a cow. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 88a29) |
| 12145 | Definitions are of what something is, and that is universal [Aristotle] |
| Full Idea: Definitions are thought to be of what something is, and what something is is in every case universal and positive. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 90b05) | |
| A reaction: This is exhibit A for those who think that Aristotelian essences concern the genus, rather than the particular. I suspect that this idea is best expressed as 'all we can say by way of definition of a particular thing involves the use of universals'. |
| 12075 | An Aristotelian definition is causal [Aristotle, by Witt] |
| Full Idea: An Aristotelian definition is causal. | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE], Bk II.2) by Charlotte Witt - Substance and Essence in Aristotle 1.5 | |
| A reaction: [She refers us to Posterior Analytics II.2] This is important if we are tempted to follow a modern line of saying that we want Aristotelian essences, and that these are definitions. We ain't thinking of dictionaries. |
| 12384 | Definition by division needs predicates, which are well ordered and thorough [Aristotle] |
| Full Idea: To establish a definition through division, you must aim for three things: you must take what is predicated in what the thing is; you must order these items as first or second; and you must ensure that these are all there are. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 97a23) | |
| A reaction: This gives an indication of the thoroughness that Aristotle expects from a definition. They aren't like dictionary definitions of words. He expects definitions to often be very lengthy (see Idea 12292). |
| 9066 | You can define objects by progressively identifying what is the same and what is different [Aristotle] |
| Full Idea: Find what is in common among items similar and undifferentiated, then do the same for items of the same kind as the first group but a different form, and so on, till you come to a single account: this will be the definition of the object. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 97b07-14) | |
| A reaction: [His example is distinguishing 'magnanimity' from 'indifference to fortune' among people] Presumably this process works for the formation of new concepts (e.g. in biology), as well as for the definition of familiars in terms of other familiars. |
| 12382 | What it is and why it is are the same; screening defines and explains an eclipse [Aristotle] |
| Full Idea: What it is and why it is are the same. What is an eclipse? Privation of light from the moon by screening of the earth. Why is there an eclipse? ...What is a harmony? A numerical ratio between high and low. Why do the high and low harmonize? The ratio. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 90a15) | |
| A reaction: This is right at the heart of Aristotelian essentialism, and (I take it) modern scientific essentialism. If you fully know what cigarette tars are, and what human cell structure is, you understand immediately why cigarettes cause cancer. |
| 1668 | An axiom is a principle which must be understood if one is to learn anything [Aristotle] |
| Full Idea: An axiom is a principle which must be grasped if anyone is going to learn anything whatever. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 72a17) |
| 12376 | Demonstrations by reductio assume excluded middle [Aristotle] |
| Full Idea: Demonstrations by reduction to the impossible assume that everything is asserted or denied. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 77a23) | |
| A reaction: This sounds like the lynchpin of classical logic. |
| 12373 | Something holds universally when it is proved of an arbitrary and primitive case [Aristotle] |
| Full Idea: Something holds universally when it is proved of an arbitrary and primitive case. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 73b33) | |
| A reaction: A key idea in mathematical logic, but it always puzzles me. If you snatch a random person in London, and they are extremely tall, does that prove that people of London are extremely tall? How do we know the arbitrary is representative? |
| 12363 | Everything is either asserted or denied truly [Aristotle] |
| Full Idea: Of the fact that everything is either asserted or denied truly, we must believe that it is the case. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 71a14) | |
| A reaction: Presumably this means that every assertion which could possibly be asserted must come out as either true or false. This will have to include any assertions with vague objects or predicates, and any universal assertions, and negative assertions. |
| 13004 | Aristotle's axioms (unlike Euclid's) are assumptions awaiting proof [Aristotle, by Leibniz] |
| Full Idea: Aristotle's way with axioms, rather than Euclid's, is as assumptions which we are willing to agree on while awaiting an opportunity to prove them | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE], 76b23-) by Gottfried Leibniz - New Essays on Human Understanding 4.07 | |
| A reaction: Euclid's are understood as basic self-evident truths which will be accepted by everyone, though the famous parallel line postulate undermined that. The modern view of axioms is a set of minimum theorems that imply the others. I like Aristotle. |
| 12377 | Mathematics is concerned with forms, not with superficial properties [Aristotle] |
| Full Idea: Mathematics is concerned with forms [eide]: its objects are not said of any underlying subject - for even if geometrical objects are said of some underlying subject, still it is not as being said of an underlying subject that they are studied. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 79a08) | |
| A reaction: Since forms turn out to be essences, in 'Metaphysics', this indicates an essentialist view of mathematics. |
| 12372 | The essence of a triangle comes from the line, mentioned in any account of triangles [Aristotle] |
| Full Idea: Something holds of an item in itself if it holds of it in what it is - e.g., line of triangles and point of lines (their essence comes from these items, which inhere in the account which says what they are). | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 73a35) | |
| A reaction: A helpful illustration of how a definition gives us the essence of something. You could not define triangles without mentioning straight lines. The lines are necessary features, but they are essential for any explanation, and for proper understanding. |
| 12369 | A unit is what is quantitatively indivisible [Aristotle] |
| Full Idea: Arithmeticians posit that a unit is what is quantitatively indivisible. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 72a22) | |
| A reaction: Presumably indeterminate stuff like water is non-quantitatively divisible (e.g. Moses divides the Red Sea), as are general abstracta (curved shapes from rectilinear ones). Does 'quantitative' presupposes units, making the idea circular? |
| 8649 | Two numbers are equal if all of their units correspond to one another [Hume] |
| Full Idea: When two numbers are so combin'd, as that the one has always a unit answering to every unit of the other, we pronounce them equal. | |
| From: David Hume (Treatise of Human Nature [1739], I.III.1) | |
| A reaction: This became known as Hume's Principle after Frege made use of it for logicism (Foundations §63). It reduces equality to something fairly simple and visual (one-to-one correspondence). But we also say that two logicians or musicians are 'equal' in ability. |
| 21291 | There is no medium state between existence and non-existence [Hume] |
| Full Idea: Betwixt unity and number there can be no medium; no more than betwixt existence and non-existence. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.2) | |
| A reaction: Just to confirm that, as you would expect, the great empiricist has no time for 'subsistence', or shadows and holes having lower grade existece. |
| 18910 | To seek truth, study the real connections between subjects and attributes [Aristotle] |
| Full Idea: If, however, one is aiming at truth, one must be guided by the real connexions of subjects and attributes. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 81b22), quoted by George Engelbretsen - Trees, Terms and Truth 3 | |
| A reaction: I take this to be a warning that predicates that indicate mere 'Cambridge properties' (such as relations, locations, coincidences etc) have nothing to do with ontology. See Shoemaker on properties. |
| 11942 | Power is the possibility of action, as discovered by experience [Hume] |
| Full Idea: Power consists in the possibility or probability of any action, as discovered by experience and the practice of the world. | |
| From: David Hume (Treatise of Human Nature [1739], p.313), quoted by George Molnar - Powers 5 | |
| A reaction: [page in OUP edn] This strikes me as blatantly false, and typical of those who confuse epistemology with ontology. It implies that a power that takes everyone by surprise is impossible, by definition. |
| 11949 | There may well be powers in things, with which we are quite unacquainted [Hume] |
| Full Idea: I am, indeed, ready to allow, that there may be several qualities both in material and immaterial objects, with which we are utterly unacquainted; and if we please to call these powers and efficiency, 'twill be be of little consequence to the world. | |
| From: David Hume (Treatise of Human Nature [1739], p.168), quoted by George Molnar - Powers 7.2.1 | |
| A reaction: A delightful air of casual indifference. What the classic empiricists needed was a notion of 'best explanation', which would allow them to leap beyond immediate experience. They made plenty of other leaps beyond experience, though Hume hated them. |
| 11950 | We have no idea of powers, because we have no impressions of them [Hume] |
| Full Idea: We never have any impression that contains any power or efficacy. We never therefore have any idea of power. | |
| From: David Hume (Treatise of Human Nature [1739], p.161), quoted by George Molnar - Powers 7.2.1 | |
| A reaction: [page in Selby-Bigges edn] It seems to me plausible that Hume is utterly wrong, because our own mental lives are a direct and constant experience of the physical powers and efficacies of material objects. |
| 11941 | The distinction between a power and its exercise is entirely frivolous [Hume] |
| Full Idea: The distinction which we sometimes make betwixt a power and the exercise of it is entirely frivolous, and ... neither man nor any other being ought ever to be thought possesst of any ability, unless it be exerted and put into action. | |
| From: David Hume (Treatise of Human Nature [1739], p.311), quoted by George Molnar - Powers 5 | |
| A reaction: [page in OUP] Molnar says this strong intuition is shared by most of us, but I take the world to be full of people who can play the piano or speak Spanish, but never actually do it. [but see Idea 11942] Most wasps never sting anything. |
| 1675 | Separate Forms aren't needed for logic, but universals (one holding of many) are essential [Aristotle] |
| Full Idea: There need be no forms (one item apart from the many) for demonstrations. But there must be universals, where one thing holds of the many. Without universals there are no middle terms, and so no demonstrations. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 77a05) |
| 1677 | We can forget the Forms, as they are irrelevant, and not needed in giving demonstrations [Aristotle] |
| Full Idea: We can say goodbye to the forms. They are nonny-noes; and if there are any they are irrelevant - for demonstrations are not concerned with them. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 83a34) |
| 11098 | Momentary impressions are wrongly identified with one another on the basis of resemblance [Hume, by Quine] |
| Full Idea: Momentary impressions, according to Hume, are wrongly identified with one another on the basis of resemblance. | |
| From: report of David Hume (Treatise of Human Nature [1739]) by Willard Quine - Identity, Ostension, and Hypostasis 3 | |
| A reaction: I don't have a Hume quotation for this yet, but Quine is plausibly claiming Hume as a resemblance nominalist, equipped with an error theory about universals. |
| 7954 | If we see a resemblance among objects, we apply the same name to them, despite their differences [Hume] |
| Full Idea: When we have found a resemblance among several objects, that often occur to us, we apply the same name to all of them, whatever differences we may observe in the degrees of their quantity and quality, and whatever other differences may appear among them. | |
| From: David Hume (Treatise of Human Nature [1739], I.I.7) | |
| A reaction: This must to some extent by right, whatever objections can be found. Russell's objection (Idea 4441) wouldn't alter the truth of Hume's observation, thought Hume is attacking universals and Russell defending them. |
| 21293 | Individuation is only seeing that a thing is stable and continuous over time [Hume] |
| Full Idea: The principle of individuation is nothing but the invariableness and uninterruptedness of any object through a supposed variation of time, by which the mind can trace it in the different periods of its existence. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.2) | |
| A reaction: Not convinced by this. I can individuate something by an almost instantaneous glimpse. I don't increasingly individuate it as time passes. Instant viewing of type and structure may be enough. |
| 1687 | Why are being terrestrial and a biped combined in the definition of man, but being literate and musical aren't? [Aristotle] |
| Full Idea: Why will a man be a two-footed terrestrial animal and not an animal and terrestrial? Assumptions do not make it necessary that what is predicated form a unity - rather, it is as if the same man were musical and literate. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 92a30) |
| 1681 | Units are positionless substances, and points are substances with position [Aristotle] |
| Full Idea: A unit is a positionless substance, and a point a substance having position. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 87a36) |
| 12048 | The only meaning we have for substance is a collection of qualities [Hume] |
| Full Idea: We have no idea of substance, distinct from that of a collection of particular qualities, nor have we any other meaning when we either talk or reason concerning it. | |
| From: David Hume (Treatise of Human Nature [1739], I.I.6) | |
| A reaction: This is the standard empiricist view of such things, firmly stated. It is tempting to say that Hume has simply misunderstood the word, since it is precisely intended to mean not the qualities, but what underlies them, and persists. |
| 13424 | Aristotelians propose accidents supported by substance, but they don't understand either of them [Hume] |
| Full Idea: The peripatetic philosophers carry their fictions still further, and both suppose a substance supporting, which they do not understand, and an accident supported, of which they have as imperfect an idea. The whole system is entirely incomprehensible. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.3) | |
| A reaction: It seems to me that if you put it to Aristotle that he didn't understand 'substantial form', he would concede the point, but nevertheless say that it was ideal at which knowledge aimed. Locke is much more astute than Hume on this. |
| 12146 | Definitions recognise essences, so are not themselves essences [Aristotle] |
| Full Idea: If a definition is the recognition of some essence, it is clear that such items are not essences. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 90b17) | |
| A reaction: So definitions are not themselves essences (as some modern thinkers claim). The idea seems obvious to me, but it is a warning against a simplistic view of Aristotelian essences, and a reminder that such things are real, not verbal. |
| 17039 | The predicates of a thing's nature are necessary to it [Aristotle] |
| Full Idea: Whatever is predicated in what something is is necessary. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 96b03) | |
| A reaction: This does NOT say that the essence is just the necessities. He goes on to say to say separately that certain properties of a triplet are part of the essence, as well as being necessary. This shows the nature of a thing is also necessary. |
| 11994 | Aristotelian essences are properties mentioned at the starting point of a science [Aristotle, by Kung] |
| Full Idea: As Aristotle uses the term 'essence', only those properties which are mentioned in or relatively close to the starting points of the science will be essential. | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE]) by Joan Kung - Aristotle on Essence and Explanation II | |
| A reaction: I take this to be the correct way to understand Aristotelian essence - as something understood by its role in scientific explanations. We may, of course, work back to the starting point of a science, by disentangling the mess in the middle. |
| 21300 | A change more obviously destroys an identity if it is quick and observed [Hume] |
| Full Idea: A change in any considerable part of a body destroys its identity; but 'tis remarkable that where the change is produced gradually and insensibly we are less apt to ascribe to it the same effect. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: Broad spotted that landscapes change too, but so slowly that we barely admit any change at all. The type of change also matters. If my car slowly changes to chocolate the speed of change is a minor factor. |
| 21299 | Changing a part can change the whole, not absolutely, but by its proportion of the whole [Hume] |
| Full Idea: Though the change of any considerable part of a mass of matter destroys the identity of the whole, yet we must measure the greatness of the part, not absolutely, but by its proportion to the whole. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: This seems to nicely demonstrate that the wholeness is in the mind of the perceiver, and does not simply depend on objective facts. Compare the proportion needed to change my pile of mud and my pile of gold. |
| 1321 | If identity survives change or interruption, then resemblance, contiguity or causation must unite the parts of it [Hume] |
| Full Idea: The objects which are variable or interrupted, and yet are supposed to continue the same, are such only as consist of a succession of parts, connected together by resemblance, contiguity, or causation. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) |
| 1330 | If a republic can retain identity through many changes, so can an individual [Hume] |
| Full Idea: As the same individual republic may not only change its members, but also its laws and constitutions; in like manner the same person may vary his character and disposition, as well as his impressions and ideas, without losing his identity. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) |
| 21302 | If a ruined church is rebuilt, its relation to its parish makes it the same church [Hume] |
| Full Idea: If a church which was formerly of brick fell to ruin, the parish can build the same church of free-stone, with modern architecture. Neither the form nor materials are the same, but their relation to the parishioners is sufficient to say they are the same. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: The clearly invites the question of whether this is type-identity or token-identity. If the parish decided they wanted two churches they obviously wouldn't be the same (even if they then demolished the first one). |
| 21303 | We accept the identity of a river through change, because it is the river's nature [Hume] |
| Full Idea: Where the objects are in their nature changeable and inconstant, we admit of a more sudden transition. The nature of a river consists in the motion and change of parts. What is expected appears of less moment than what is unusual and extraordinary. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: Aha! Little does Hume realise how Aristotelian he is! Aristotle may have a more objective view of the 'nature' of a thing, but making inferences about identity over time from a thing's essential nature is pure Aristotle. |
| 21301 | The purpose of the ship makes it the same one through all variations [Hume] |
| Full Idea: The common end [of a ship], in which the parts conspire, is the same under all variations, and affords an easy transition of the imagination from one situation of the body to another. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: It is not true that a ship remains the same under ALL variations. Consider gradually changing a yacht into a racing powerboat. You might say the purpose is then changed, but the slight variations in a yacht can slightly change its purpose. |
| 21290 | Multiple objects cannot convey identity, because we see them as different [Hume] |
| Full Idea: A mutiplicity of objects can never convey the idea of identity. The mind always pronounces the one not to be the other. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.2) | |
| A reaction: However, if we are talking on the phone about two objects we are viewing, such as two buildings, our descriptions might lead us to conclude that our objects are identical. Thus experience might imply identity. |
| 1207 | Both number and unity are incompatible with the relation of identity [Hume] |
| Full Idea: Both number and unity are incompatible with the relation of identity. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.2) |
| 21289 | 'An object is the same with itself' is meaningless; it expresses unity, not identity [Hume] |
| Full Idea: In that proposition 'an object is the same with itself', if the idea expressed by the word 'object' were no way distinguished from that meant by 'itself', we should really mean nothing. ...One single object conveys the idea of unity, not that of identity. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.2) | |
| A reaction: As far as I can see it is mathematicians who like self-identity, to justify x=x, which they need. To say 'this vase is identical with itself' is an empty locution. It expresses either unity or stability over time. See Idea 21292. |
| 21292 | Saying an object is the same with itself is only meaningful over a period of time [Hume] |
| Full Idea: We cannot, in any propriety of speech, say that an object is the same with itself, unless we mean that the object existent at one time is the same with itself at another time. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.2) | |
| A reaction: This seems correct, but the strict language of identity is superfluous when identifying stolen goods. 'This is my watch', not 'this watch is identical with my watch'. |
| 12381 | What is necessary cannot be otherwise [Aristotle] |
| Full Idea: What is necessary cannot be otherwise. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 88b32) | |
| A reaction: If the next interesting question is the source of necessity, then the question seems to be 'what prevents it from being otherwise?'. |
| 1690 | A stone travels upwards by a forced necessity, and downwards by natural necessity [Aristotle] |
| Full Idea: There are two types of necessity, one according to nature and impulse, the other by force and contrary to impulse. A stone travels upwards and downwards from different necessities. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 94b38) |
| 9428 | Nothing we clearly imagine is absolutely impossible [Hume] |
| Full Idea: 'Tis an established maxim in metaphysics, that whatever the mind clearly conceives includes the idea of possible existence, or in other words, that nothing we imagine is absolutely impossible. | |
| From: David Hume (Treatise of Human Nature [1739], I.II.2) | |
| A reaction: It is important to note that this empiricist approach to what is impossible requires that we 'clearly' conceive the possibility - but how do we evaluate whether we are being clear or not? |
| 4766 | Necessity only exists in the mind, and not in objects [Hume] |
| Full Idea: Necessity …is nothing but an internal impression of the mind, or a determination to carry our thoughts from one object to another. | |
| From: David Hume (Treatise of Human Nature [1739], I.III.16) | |
| A reaction: The classic statement of the empiricist position. Personally I don't believe it. Non-mental necessities are likely to be natural, or to be features of 'Platonic' objects. A big issue… |
| 12072 | For Aristotle knowledge is explanatory, involving understanding, and principles or causes [Aristotle, by Witt] |
| Full Idea: For Aristotle, knowledge is explanatory, for to know something is to understand it, and to understand something is to grasp its principles or causes. | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE]) by Charlotte Witt - Substance and Essence in Aristotle 1.2 | |
| A reaction: Thus the kind of 'knowledge' displayed in quiz shows would not count as knowledge at all, if it was mere recall of facts. To know is to be able to explain, which is to be able to teach. See Idea 11241. |
| 12073 | 'Episteme' means grasping causes, universal judgments, explanation, and teaching [Aristotle, by Witt] |
| Full Idea: For Aristotle, a person who has 'episteme' grasps the cause of a given phenomenon, can make a universal judgment about it, can explain it, and can teach others about it. | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE]) by Charlotte Witt - Substance and Essence in Aristotle 1.2 | |
| A reaction: This I take to be the context in which we should understand what Aristotle means by an 'essence' - it is the source of all of the above, so it both makes a thing what it is, and explains why it shares features with other such things. |
| 12378 | The reason why is the key to knowledge [Aristotle] |
| Full Idea: Study of the reason why has the most importance for knowledge. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 79a24) | |
| A reaction: I take the study of reasons for belief to be much more central to epistemology than finding ways to answer radical sceptics about the basic possibility of knowledge. |
| 12364 | We understand a thing when we know its explanation and its necessity [Aristotle] |
| Full Idea: We understand something simpliciter when we think we know of the explanation because of which the object holds that it is its explanation, and also that it is not possible for it to be otherwise. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 71b10) | |
| A reaction: The second half sounds odd, since we ought to understand that something could have been otherwise, and knowing whether or not it could have been otherwise is part of the understanding. It sounds like Spinozan determinism. |
| 12366 | We only understand something when we know its explanation [Aristotle] |
| Full Idea: We only understand something when we know its explanation. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 71b30) | |
| A reaction: If we believe that the whole aim of philosophy is 'understanding' (Idea 543) - and if it isn't then I am not sure what the aim is, and alternative aims seem a lot less interesting - then we should care very much about explanations, as well as reasons. |
| 12370 | Some understanding, of immediate items, is indemonstrable [Aristotle] |
| Full Idea: Not all understanding is demonstrative: rather, in the case of immediate items understanding is indemonstrable. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 72b19) | |
| A reaction: These are the foundations of Aristotle's epistemology, and I take it that they can be both empiricist and rationalist - sense experiences, and a priori intuitions. |
| 1685 | No one has mere belief about something if they think it HAS to be true [Aristotle] |
| Full Idea: No one holds something as an opinion when he thinks that it is impossible for it to be otherwise - for then he thinks he understands it. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 89a07) |
| 1673 | Knowledge proceeds from principles, so it is hard to know if we know [Aristotle] |
| Full Idea: It is difficult to know whether you know something or not. For it is difficult to know whether or not our knowledge of something proceeds from its principles - and this is what it is to know something. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 76a25) |
| 6526 | Hume says objects are not a construction, but an imaginative leap [Hume, by Robinson,H] |
| Full Idea: Hume's idea is that we move from private impressions to the physical world, not by an unconscious analytical construction but by a spontaneous imaginative leap. | |
| From: report of David Hume (Treatise of Human Nature [1739]) by Howard Robinson - Perception IX.6 | |
| A reaction: The idea that objects are 'constructions' seems to have originated with Russell. Hume seems closer to the actual process, which is virtually instantaneous. They both forget that you can follow up the construction or leap with a cool evaluation. |
| 12379 | You cannot understand anything through perception [Aristotle] |
| Full Idea: You cannot understand anything through perception. Demonstrations are universal, and universals cannot be perceived. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 87b28) |
| 16725 | Some knowledge is lost if you lose a sense, and there is no way the knowledge can be replaced [Aristotle] |
| Full Idea: The loss of any one of the senses entails the loss of a corresponding portion of knowledge, and since we learn either by induction or by demonstration, this knowledge cannot be acquired. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 81a37) | |
| A reaction: This suggests Jackson's 'knowledge argument', that raw experience contains some genuine knowledge, for which there is no mechanistic substitute. Not that I accept…. |
| 6489 | Associationism results from having to explain intentionality just with sense-data [Robinson,H on Hume] |
| Full Idea: The limited theories of Berkeley and Hume have to be reductive, because they have to explain intentionality in terms of some kind of relation between sense-data; this predicament gives rise to the associationist accounts of psychology and meaning. | |
| From: comment on David Hume (Treatise of Human Nature [1739]) by Howard Robinson - Perception 1.4 | |
| A reaction: An illuminating explanation. Robinson seems to be implying that we should accept something like Searle's 'intrinsic' intentionality as basic, rather than intentionality built up from smaller components as Hume and Dennett suggest. |
| 23309 | Aristotle's concepts of understanding and explanation mean he is not a pure empiricist [Aristotle, by Frede,M] |
| Full Idea: It is a certain notion of understanding and, correspondingly, explanation which makes Aristotle think that knowledge, properly speaking, could not be a matter of mere experience. | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE]) by Michael Frede - Aristotle's Rationalism p.160 | |
| A reaction: Frede says this means that Aristotle is a rationalist, though few empiricists think understanding is 'merely' a matter of experience. My own epistemology is Explanatory Empiricism, which I see as more empiricist than rationalist. |
| 1693 | Animals may have some knowledge if they retain perception, but understanding requires reasons to be given [Aristotle] |
| Full Idea: In some animals the perception is retained, and in some not. Without retention knowledge is impossible. Some animals go further and form an account based on the perception. This leads to memory and experience, and so to either skill or understanding. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 99b35-) |
| 6182 | Even Hume didn't include mathematics in his empiricism [Hume, by Kant] |
| Full Idea: Even Hume did not make empiricism so universal as to include mathematics in it. | |
| From: report of David Hume (Treatise of Human Nature [1739]) by Immanuel Kant - Critique of Practical Reason Pref | |
| A reaction: Hume didn't actually exclude mathematics, and the notion of 'relations of ideas' is a pointer. Subsequent empiricist have offered promising accounts. Personally I like the idea that patterns are the key idea. |
| 9067 | Many memories of the same item form a single experience [Aristotle] |
| Full Idea: When it occurs often in connection with the same item, ..memories which are many in number form a single experience. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 100a05) | |
| A reaction: This is Aristotle at his most empirical. He is not describing an operation of the understanding, but a process of association. The process he alludes to is at the heart of the abstractionist view of concept-formation. |
| 1671 | Sceptics say justification is an infinite regress, or it stops at the unknowable [Aristotle] |
| Full Idea: Sceptics say that there is either an infinite regress of ideas based on one another, or things come to a stop at primitives which are unknowable (because they can't be demonstrated). | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 72b09) | |
| A reaction: This is one strand of what eventually becomes the classic Agrippa's Trilemma (Idea 8850). For Aristotle's view on this one, see Idea 562. |
| 1670 | When you understand basics, you can't be persuaded to change your mind [Aristotle] |
| Full Idea: Anyone who understands anything simpliciter (as basic) must be incapable of being persuaded to change his mind. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 72b04) | |
| A reaction: A typical Aristotle test which seems rather odd to us. Surely I can change my mind, and decide that something is not basic after all? But, says Aristotle, then you didn't really think it was basic. |
| 12417 | Mathematicians only accept their own proofs when everyone confims them [Hume] |
| Full Idea: There is no Mathematician so expert as to place entire confidence in any truth upon his discovery of it. ..Every time he runs over his proofs his confidence encreases, ..and is rais'd to perfection by the applause of the learned world. | |
| From: David Hume (Treatise of Human Nature [1739], IV.1.4) | |
| A reaction: [compressed] Quoted by Kitcher, and a nice example of the social nature of 'warrants', even in mathematics. It was illustrated well in the 1990s by the story of the proof of Fermat's Last Theorem by Andrew Wiles. |
| 5548 | Hume became a total sceptic, because he believed that reason was a deception [Hume, by Kant] |
| Full Idea: David Hume gave way entirely to scepticism, since he believed himself to have discovered in what is generally held to be reason a deception of our faculty of cognition. | |
| From: report of David Hume (Treatise of Human Nature [1739]) by Immanuel Kant - Critique of Pure Reason B128 | |
| A reaction: Unfair to Hume, who was very opposed to global scepticism (see Ideas 2240 and 2241), and voted only for 'mitigated scepticism' (see Idea 2242). On the other hand, there is no greater opposition in philosophy than Kant and Hume on 'pure reason'. |
| 1674 | All demonstration is concerned with existence, axioms and properties [Aristotle] |
| Full Idea: All demonstrative science [apodeiktike episteme] is concerned with three things: what it posits to exist (the kind), the axioms (primitives basic to demonstration), and the attributes. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 76b12) |
| 24068 | Demonstration is more than entailment, as the explanatory order must match the causal order [Aristotle, by Koslicki] |
| Full Idea: Aristotle's demonstration encompasses more than deductive entailment, in that the explanatory order of priority represented in a successful demonstration must mirror precisely the causal order of priority in the phenomena in question. | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE]) by Kathrin Koslicki - Form, Matter and Substance 4.5 | |
| A reaction: Interesting. I presume this is correct, but is not an aspect I had registered. In Metaphysics his essentialist explanations are causal, so it all hangs together. |
| 17310 | Aristotle gets asymmetric consequence from demonstration, which reflects real causal priority [Aristotle, by Koslicki] |
| Full Idea: In Aristotle's system, the relevant notion of asymmetric consequence that is operative in his model of scientific explanation is that of demonstration. ...It is a theoretical/linguistic reflection of an asymmetric real-world relation of causal priority. | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE]) by Kathrin Koslicki - Varieties of Ontological Dependence 7.3 n7 | |
| A reaction: The asymmetry is required for explanation, and for grounding. |
| 21359 | Aristotle doesn't actually apply his theory of demonstration to his practical science [Leroi on Aristotle] |
| Full Idea: There is a conflict between the syllogistic theory of demonstration of the Posterior Analytics, with its austere programme of certainties, and how Aristotle actually does science. | |
| From: comment on Aristotle (Posterior Analytics [c.327 BCE]) by Armand Marie LeRoi - The Lagoon: how Aristotle invented science 104 | |
| A reaction: Leroi observes that there are no demonstrations anywhere in the biological writings. Biology probably lends itself least to such an approach. |
| 1667 | Premises must be true, primitive and immediate, and prior to and explanatory of conclusions [Aristotle] |
| Full Idea: Demonstrative understanding must proceed from items which are true and primitive and immediate and more familiar and prior to and explanatory of the conclusions. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 71b22) |
| 12365 | We can know by demonstration, which is a scientific deduction leading to understanding [Aristotle] |
| Full Idea: We know things through demonstration, by which I mean a scientific deduction, and by 'scientific' I mean a deduction by possessing which we understand something. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 71b17) | |
| A reaction: This is a distinctively Aristotelian account of what science aims at, and which seems to have dropped out of modern accounts of science, which are still under the influence of logical positivism. Time to revive it. |
| 10918 | Demonstrative understanding rests on necessary features of the thing in itself [Aristotle] |
| Full Idea: If demonstrative understanding proceeds from necessary principles, and whatever holds of an object in itself is necessary, then it is clear that demonstrative deductions will proceed from certain items of this sort. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 74b05-) | |
| A reaction: This is the characterization of the essence of something in terms of what counts as a good explanation of that thing. Although explanation is a bit subjective, I like this approach, because you will dig down to the source of the powers of the thing. |
| 12374 | Demonstrations must be necessary, and that depends on the middle term [Aristotle] |
| Full Idea: If you understand something demonstratively, it must hold from necessity, so it is plain that your demonstration must proceed through a middle term which is necessary. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 75a13) | |
| A reaction: How can a middle 'term' be necessary, if it is not a proposition? Presumably Socrates is necessarily a man, and men are necessarily mortal, so it is the predication which is necessary. |
| 12148 | Demonstrations are syllogisms which give explanations [Aristotle] |
| Full Idea: Demonstrations are probative deductions [sullogismos] which give the explanation [aitias] and the reason why. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 85b24) | |
| A reaction: This notion seems to have slipped out of modern philosophy of science, because (while scientists have just pressed on) philosophers of science have raised so many sceptical questions that they have, I would say, lost the plot. |
| 1679 | Universal demonstrations are about thought; particular demonstrations lead to perceptions [Aristotle] |
| Full Idea: Universal demonstrations are objects of thought, particular demonstrations terminate in perception. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 86a30) |
| 1680 | Demonstration is better with fewer presuppositions, and it is quicker if these are familiar [Aristotle] |
| Full Idea: A demonstration is superior if it depends on fewer suppositions or propositions - for if these are familiar, knowledge will come more quickly, and this is preferable. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 86a35) |
| 1691 | Aim to get definitions of the primitive components, thus establishing the kind, and work towards the attributes [Aristotle] |
| Full Idea: Divide a whole into its primitives, then try to get definitions of these. Thus you establish the kind, and then study the attributes through the primitive common items. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 96b16) |
| 12383 | There must be definitions before demonstration is possible [Aristotle] |
| Full Idea: There is no demonstration of anything of which there is no definition. Definitions are of what something is, i.e. of its essence, but all demonstrations clearly suppose and assume what a thing is. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 90b30) | |
| A reaction: Note that while essentialism rests on definitions, the job is not yet complete once the definitions are done. With good definitions, it should be easy to show how the pieces of the jigsaw fit together. |
| 12371 | A demonstration is a deduction which proceeds from necessities [Aristotle] |
| Full Idea: A demonstration is a deduction which proceeds from necessities. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 73a24) | |
| A reaction: Elsewhere he tells us that demonstration that brings understanding (Idea 12365), so this is an interesting gloss. He says that the middle term of the syllogism gives the understanding, but necessities reside in the whole propositions of the premisses. |
| 12147 | The principles of demonstrations are definitions [Aristotle] |
| Full Idea: The principles of demonstrations are definitions. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 90b25) | |
| A reaction: This I take to be a key idea linking Aristotle's desire to understand the world, by using demonstrations to reach good explanations. Definitions turn out to rest on essences, so our understanding of the world rests on essences. |
| 7446 | The idea of inductive evidence, around 1660, made Hume's problem possible [Hume, by Hacking] |
| Full Idea: Hume's sceptical problem of induction could not have arisen much before 1660, for there was no concept of inductive evidence in terms of which to raise it. | |
| From: report of David Hume (Treatise of Human Nature [1739]) by Ian Hacking - The Emergence of Probability Cont 19 | |
| A reaction: Hacking is the expert, but Ideas 1683 and 1886 suggest there was some thinking on the problem in the ancient world. The worry about whether the future would be like the past must occasionally have bothered someone. |
| 1683 | We learn universals from many particulars [Aristotle] |
| Full Idea: It is from many particulars that the universal becomes plain. Universals are valuable because they make the explanation plain. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 88a05) |
| 12367 | What is most universal is furthest away, and the particulars are nearest [Aristotle] |
| Full Idea: What is most universal is furthest away, and the particulars are nearest. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 72a05) | |
| A reaction: This is the puzzle that bother Aristotle about explanation, that we can only grasp the universals, when we want to explain the particulars. |
| 12380 | Universals are valuable because they make the explanations plain [Aristotle] |
| Full Idea: Universals are valuable because they make the explanations plain. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 88a06) | |
| A reaction: Everything in Aristotle comes back to human capacity to understand. There seems to be an ideal explanation consisting entirely of particulars, but humans are not equipped to grasp it. We think in a broad brush way. |
| 12385 | Are particulars explained more by universals, or by other particulars? [Aristotle] |
| Full Idea: Which of the middle terms is explanatory for the particulars - the one which is primitive in the direction of the universal, or the one which is primitive in the direction of the particular? | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 99b09) | |
| A reaction: I'm not clear about this, but it shows Aristotle wrestling with the issue of whether explanations are of particulars or universals, and whether they employ particulars as well as employing universals. The particular must be defined! |
| 1689 | Explanation is of the status of a thing, inferences to it, initiation of change, and purpose [Aristotle] |
| Full Idea: There are four sorts of explanation: what it is to be something, that if certain items hold it is necessary for this to hold, what initiated the change, and the purpose. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 94a21) | |
| A reaction: This might be summed up as: 'we want to know the essence, the necessary conditions, the cause, and the purpose'. Can anyone improve on that as the aims of explanation? The second explanation (necessary preconditions) isn't in 'Physics' - Idea 8332. |
| 1686 | What we seek and understand are facts, reasons, existence, and identity [Aristotle] |
| Full Idea: The things we seek are equal in number to those we understand: the fact, the reason why, if something is, and what something is. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 89b24) |
| 12357 | Explanation and generality are inseparable [Aristotle, by Wedin] |
| Full Idea: For Aristotle, explanation and generality are fellow-travellers. | |
| From: report of Aristotle (Posterior Analytics [c.327 BCE]) by Michael V. Wedin - Aristotle's Theory of Substance X.11 | |
| A reaction: This isn't 'lawlike' explanation, but it is interestingly close to it. It seems to be based on the fact that predicates are universals, so we can only state truths in general terms. |
| 1669 | The foundation or source is stronger than the thing it causes [Aristotle] |
| Full Idea: Something always holds better because of that because of which it holds - e.g. that because of which we love something is better loved. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 72a30) |
| 1678 | Universals give better explanations, because they are self-explanatory and primitive [Aristotle] |
| Full Idea: Universals are more explanatory (for something which holds in itself is itself explanatory of itself; and universals are primitive; hence universals are explanatory) - so universal demonstrations are better. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 85b25) |
| 21806 | Memory, senses and understanding are all founded on the imagination [Hume] |
| Full Idea: The memory, senses, and understanding are all of them founded on the imagination, or the vivacity of our ideas. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.7.3), quoted by Stephan Schmid - Faculties in Early Modern Philosophy 5 | |
| A reaction: He seems to have in mind his theory of associations, which are not rational. |
| 9068 | Perception creates primitive immediate principles by building a series of firm concepts [Aristotle] |
| Full Idea: Primitive immediate principles ...come about from perception - as in a battle, when a rout has occurred, first one man makes a stand, then another, and then another, until a position of strength is reached. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 100a12) | |
| A reaction: Philosophers don't create imagery like that any more. This empiricist account of how concepts and universals are created is part of a campaign against Plato's theory of forms. [Idea 9069 continues his idea] |
| 9069 | A perception lodging in the soul creates a primitive universal, which becomes generalised [Aristotle] |
| Full Idea: When one undifferentiated item in perception makes a stand, there is a primitive universal in the soul; for although you perceive particulars, perception is of universals - e.g. of man, not of Callias the man. One animal makes a stand, until animal does. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 100a15-) | |
| A reaction: This is the quintessential account of abstractionism, with the claim that primitive universals arise directly in perception, but only in repeated perception. How the soul does it is a mystery to Aristotle, just as associations are a mystery to Hume. |
| 3819 | Hume's 'bundle' won't distinguish one mind with ten experiences from ten minds [Searle on Hume] |
| Full Idea: Hume's thought that each perception is separate and distinct cannot be right, because then we can't distinguish between one consciousness with ten experiences and ten different consciousnesses. | |
| From: comment on David Hume (Treatise of Human Nature [1739]) by John Searle - Rationality in Action Ch.3.VI | |
| A reaction: Why can't the only connection between them be that they all occur to the speaker who reports to them? How would I know if one of 'my' mental events actually belonged to a neighbour and had strayed. If it was coherent, I would accept it. |
| 1317 | A person is just a fast-moving bundle of perceptions [Hume] |
| Full Idea: I affirm of the rest of mankind, that they are nothing but a bundle or collection of different perceptions, which succeed each other with an inconceivable rapidity, and are in perpetual flux and movement. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: Note that Hume is not just saying what we can know of ourselves, but is asserting a view of what we actually are. The minimal objection to this is to ask how we know that a perception is a member of one big bundle rather than several small ones. |
| 1331 | The parts of a person are always linked together by causation [Hume] |
| Full Idea: Whatever changes a person endures, his several parts are still connected by the relation of causation. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: However, the opposite ends of the universe are linked together by causation, so that will not suffice for a theory of personal identity. One might try to specify a complex and tight network of causation (like a brain!) instead of just 'connection'. |
| 1388 | Hume gives us an interesting sketchy causal theory of personal identity [Perry on Hume] |
| Full Idea: I believe Hume offers an interesting if sketchy theory of personal identity, a causal theory, disguised as the revolutionary discovery that there is no such thing as personal identity | |
| From: comment on David Hume (Treatise of Human Nature [1739], I.IV.6) by John Perry - Introduction to 'Personal Identity' Intro | |
| A reaction: There is certainly a theory there, even though Hume ceased to believe in it, which is nowadays covered by the idea that personal identity is a 'fiction', an arbitrary idea that reifies the focus and direction of a bundle of mental events. |
| 21297 | A person is simply a bundle of continually fluctuating perceptions [Hume] |
| Full Idea: [People] are nothing but a bundle or collection of different perceptions, which succeed each other with an inconceivable rapidity, and are in a continual flux and movement. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: Nowadays we must say that this misses the huge non-conscious aspect of what a person is. He seems to see all mental events as equal. Isn't the experience of deciding to focus on this sentence more 'central' than awareness of your feet? |
| 1316 | Introspection always discovers perceptions, and never a Self without perceptions [Hume] |
| Full Idea: I never can catch myself at any time without a perception, and never can observe any thing but the perception. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: The first half can hardly be denied, but I think the second half is just false. What you observe is not just a raw neutral sense-datum, floating in nothing, but a sense-datum that is deeply coloured by MY interests, interpretations and values. |
| 1333 | Memory only reveals personal identity, by showing cause and effect [Hume] |
| Full Idea: Memory does not so much produce as discover personal identity, by showing us the relation of cause and effect among our different perceptions. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: This is a rather strained proposal, as the revelation of a network of cause and effect seems to have no implications for personal identity (unless only 'I' could be the cause). |
| 1332 | We use memory to infer personal actions we have since forgotten [Hume] |
| Full Idea: We can extend the chain of causes acquired from memory, and consequently the identity of our persons beyond our memory, and can comprehend times, and circumstances, and actions, which we have entirely forgot. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: If the principle is just that 'I am my consciousness' (including of my past), then why should not my consciousness of other people's pasts by included in my identity. How do I know that images in my consciousness are MY memories? |
| 21305 | Memory not only reveals identity, but creates it, by producing resemblances [Hume] |
| Full Idea: The memory not only discovers the identity [of the mind], but also contributes to its production, by producing the relation of resemblance among the perceptions | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: This is Hume battling to explain personal identity by his principles of association. He discount 'contiguity'. He doesn't explain how memory creates resemblances. Is not resemblance of idea to fact required in order to remember? |
| 21307 | Who thinks that because you have forgotten an incident you are no longer that person? [Hume] |
| Full Idea: Who will affirm, because he has entirely forgot the incidents of past days, that the present self is not the same person with the self of that time? And by that means overturn all the most established notions of personal identity? | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: This is a swipe at one of Locke's most controversial claims (especially when applied to incidents of criminal behaviour). Hume says memory constitutes this identity, but Locke's view says it merely reveals identity. |
| 21306 | Causation unites our perceptions, by producing, destroying and modifying each other [Hume] |
| Full Idea: As to causation, the true idea of the human mind is to consider it as a system of different perceptions, which are linked together by the relation of cause and effect, and mutually produce, destroy, influence and modify each other. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: He suggests that the associations of memory and causation might be sufficient to produce identity of the mind, and he gives the priority to memory. Eventually the good empiricist despairs because you cannot experience the links. |
| 21294 | A continuous lifelong self must be justified by a single sustained impression, which we don't have [Hume] |
| Full Idea: If any impression gives rise to the idea of self, that impression must continue invariably the same, through the whole course of our lives; since self is supposed to exist after that manner. But there is no impression constant and invariable. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: This is a rather dogmatic application of the requirement that all knowledge must be founded in experience. It fails to recognise that knowledge of the thing having the experiences is a rather special case. We must ask for the best explanation. |
| 21295 | When I introspect I can only observe my perceptions, and never a self which has them [Hume] |
| Full Idea: When I enter most intimately into myself I always stumble on some particular perception or other, of heat or cold, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never observe any thing but the perception. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: It isn't like looking for your car in the car park. The prior question should be: assuming you do have a persisting self, what would you expect introspection to reveal about it? |
| 21298 | We pretend our perceptions are continuous, and imagine a self to fill the gaps [Hume] |
| Full Idea: We feign the continued existence of the perceptions of our senses, to remove their interruption; and run into the notion of a soul, and self, and substance, to disguise the variation. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: Modern neuroscience (according to Dennett) endorses this, because the brain continually fills in gaps in experience (as it fills in the blindspot during normal vision). |
| 21304 | Identity in the mind is a fiction, like that fiction that plants and animals stay the same [Hume] |
| Full Idea: The identity we ascribe to the mind is only a fictitious one, and of a like kind with that we ascribe to vegetable and animal bodies. It cannot therefore have a different origin, but must proceed from a like operation of the imagination upon like objects. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: Sustained purpose is Hume's common factor. Is the identity over time ascribed to the body of a single animal nothing more than a fiction? It is a wise ascription, compared to stupid ascriptions to gerrymandered objects. |
| 9070 | We learn primitives and universals by induction from perceptions [Aristotle] |
| Full Idea: We must get to know the primitives by induction; for this is the way in which perception instils universals. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 100b04) | |
| A reaction: This statement is so strongly empirical it could have come from John Stuart Mill. The modern post-Fregean view of universals is essentially platonist - that they have a life and logic of their own, and their method of acquisition is irrelevant. |
| 12368 | Negation takes something away from something [Aristotle] |
| Full Idea: The part of a contradictory pair which says something of something is an affirmation; the part which takes something from something is a negation. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 72a14) | |
| A reaction: So affirmation is predication about an object ['Fa'], and negation is denial of predication. We have a scope problem: there is nothing which is F [¬∃x(Fx)], or there is a thing which is not-F [∃x(¬Fx)]. Aristotle seems to mean the latter. |
| 1692 | If you shouldn't argue in metaphors, then you shouldn't try to define them either [Aristotle] |
| Full Idea: If you should not argue in metaphors, it is plain too that you should neither define by metaphors nor define what is said in metaphors; for then you will necessarily argue in metaphors. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 97b37) | |
| A reaction: Impeccable logic, but seeing a similarity can be a wonderful shortcut to seeing a great truth. |
| 20030 | If one event causes another, the two events must be wholly distinct [Hume, by Wilson/Schpall] |
| Full Idea: Hume's maxim is that if one event cause another, then the two events must be wholly distinct. | |
| From: report of David Hume (Treatise of Human Nature [1739]) by Wilson,G/Schpall,S - Action 3 | |
| A reaction: [Anyone know the original reference?] So we are not allowed to say that one part of an event caused another. The charged caused the victory, so they are two events, but in another context the whole battle is one event. |
| 6692 | For Hume, practical reason has little force, because we can always modify our desires [Hume, by Graham] |
| Full Idea: In Hume's account of action, practical reason is not a very forceful guide to conduct, since we can escape its demands by abandoning or modifying our desires. | |
| From: report of David Hume (Treatise of Human Nature [1739]) by Gordon Graham - Eight Theories of Ethics Ch.6 | |
| A reaction: Presumably a desire can be a good reason, and we can passionately desire to be rational, etc., so this is a rather complex issue. 'Pure reason' is not 'all-or-nothing', and neither is pure desire. |
| 8257 | Reason alone can never be a motive to any action of the will [Hume] |
| Full Idea: Reason alone can never be a motive to any action of the will. | |
| From: David Hume (Treatise of Human Nature [1739], II.III.3) | |
| A reaction: This is Hume's notorious total rejection of Socratic intellectualism, a stilleto in the back of the 'age of reason'. Hume thinks desire is the motivator. He's probably right. Why should truth motivate? See Idea 4421. |
| 22374 | You can only hold people responsible for actions which arise out of their character [Hume] |
| Full Idea: Where actions proceed not from some cause in the characters and dispositions of the person who performed them, they infix not themselves upon him, and can neither redound to his honour if good, nor infamy if evil. The action in itself may be blameable. | |
| From: David Hume (Treatise of Human Nature [1739], II.III.2), quoted by Philippa Foot - Free Will as Involving Determinism p.70 | |
| A reaction: I agree with Foot that this is wrong. Uncharacteristic actions still reflect on the person. The last sentence is wrong too. If you ignore the agent of an action, it can't be distinguished from a flash of lightning. |
| 22382 | We cannot discover vice by studying a wilful murder; that only arises from our own feelings [Hume] |
| Full Idea: Examine wilful murder and see if you can find the matter of fact called vice. You only find certain passions, motives, volitions and thoughts. There is no matter of fact in the case. You can never find it till you turn your reflexion into your own breast. | |
| From: David Hume (Treatise of Human Nature [1739], III.I.2), quoted by Philippa Foot - Hume on Moral Judgement p.77 | |
| A reaction: [...In you breast you find 'disapprobation'] The question Foot asks is whether the facts of the case are relevant to the disapprobation. If they are not, as Hume implies, then it would be rational to feel the same disapprobation about drinking coffee. |
| 4008 | Modern science has destroyed the Platonic synthesis of scientific explanation and morality [Hume, by Taylor,C] |
| Full Idea: From our modern perspective, the Platonic synthesis of scientific explanation and moral insight lies irrecoverably shattered by the rise of natural science. | |
| From: report of David Hume (Treatise of Human Nature [1739]) by Charles Taylor - Sources of the Self §3.2 | |
| A reaction: Modern attempts to challenge Hume's separation of fact from value have failed, but a return to the Greek perspective presents a plausible alternative. |
| 8067 | The problem of getting to 'ought' from 'is' would also apply in getting to 'owes' or 'needs' [Anscombe on Hume] |
| Full Idea: Hume's objection to passing from 'is' to 'ought' would equally apply to passing from 'is' to 'owes' or from 'is' to 'needs'. | |
| From: comment on David Hume (Treatise of Human Nature [1739]) by G.E.M. Anscombe - Modern Moral Philosophy p.176 | |
| A reaction: Profound and important. The empirical and emotivist (nay, nihilist) clinging to the total independence of duties from facts crumbles when looking at facts of human nature or of social groups. Creatures ought to feed; societies ought to flourish. |
| 4578 | You can't move from 'is' to 'ought' without giving some explanation or reason for the deduction [Hume] |
| Full Idea: In many writers I find that instead of the usual propositions 'is' and 'is not', I then find no proposition that is not connected with an 'ought' or an 'ought not'. It is necessary that a reason be given for how one can be a deduction from the other. | |
| From: David Hume (Treatise of Human Nature [1739], III.1.1) | |
| A reaction: A huge claim, the basis of the value-free modern scientific world view. Possible escapes are Greek virtue theory, or Kantian principles, or some sort of a priori values (as in Charles Taylor). |
| 3650 | Total selfishness is not irrational [Hume] |
| Full Idea: It is not contrary to reason to prefer the destruction of the whole world to the scratching of my finger. | |
| From: David Hume (Treatise of Human Nature [1739], II.III.ii) | |
| A reaction: A famous idea, and the embodiment of moral nihilism. I say nothing could ever refute someone who held such a view. No moral theory can force someone to care, if they just don't. |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
| From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
| A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
| 14301 | We have no good concept of solidity or matter, because accounts of them are all circular [Hume] |
| Full Idea: In order to form an idea of solidity, we must conceive two bodies pressing on each other without penetration. ..The ideas of secondary qualities are excluded, and the idea of motion depends on extension. This leaves us no just idea of solidity or matter. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.4), quoted by Stephen Mumford - Dispositions 02.3 | |
| A reaction: [compressed] For me these kind of strict empiricist arguments always recede when you accept the notion of an inference to be best explanation. We have some sort of notion of 'matter', but here the physicist seems to take over. |
| 12375 | Whatever holds of a kind intrinsically holds of it necessarily [Aristotle] |
| Full Idea: In each kind, whatever holds of something in itself and as such holds of it from necessity. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 75a30) | |
| A reaction: This seems to confirm the view that essential properties are necessary, but it does not, of course, follow that all necessary properties are essential properties (e.g. trivial necessities are not essential). |
| 8382 | For Hume a constant conjunction is both necessary and sufficient for causation [Hume, by Crane] |
| Full Idea: Hume held that constant conjunction between As and Bs is both necessary and sufficient for a causal relation. If As and Bs are conjoined that is sufficient for a causal relation; if A and B are causally related, necessarily they are constantly conjoined. | |
| From: report of David Hume (Treatise of Human Nature [1739]) by Tim Crane - Causation 1.2.2 | |
| A reaction: A helpful connection between Hume and the modern debate about conditions for causation (e.g. Mackie). It sounds as if, to spot the necessary condition, you need to independently see that A and B are causally related, which regularity does not allow. |
| 19274 | Hume seems to presuppose necessary connections between mental events [Kripke on Hume] |
| Full Idea: A well-known objection to Hume's analysis of causation is that he presupposes necessary connections between mental events in the theory. | |
| From: comment on David Hume (Treatise of Human Nature [1739]) by Saul A. Kripke - Wittgenstein on Rules and Private Language n 87 | |
| A reaction: Are these the associations that occur within the mind? I'm not clear about the objection, but record it for interest. |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
| From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |
| 1688 | Properties must be proved, but not essence; but existents are not a kind, so existence isn't part of essence [Aristotle] |
| Full Idea: Everything which a thing is must be proved through a demonstration - except its essence. But existence is not the essence of anything; for the things that exist do not constitute a kind. | |
| From: Aristotle (Posterior Analytics [c.327 BCE], 92b14) |
| 21296 | If all of my perceptions were removed by death, nothing more is needed for total annihilation [Hume] |
| Full Idea: Were all my perceptions removed by death, and I could I neither think nor feel nor see nor love nor hate, after the dissolution of my body, I should be enitrely annihilated, nor do I conceive what is further requisite to make me a perfect non-entity. | |
| From: David Hume (Treatise of Human Nature [1739], I.IV.6) | |
| A reaction: 'A perfect non-entity'. How about that for an eighteenth century rejection of immortality of the soul? In the context, his point is that the has no enduring self, apart from this range of experiences. |