87 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. |
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'. |
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. |
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. |
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? |
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. |
4444 | One moderate nominalist view says that properties and relations exist, but they are particulars [Armstrong] |
Full Idea: There is a 'moderate' nominalism (found in G.F.Stout, for example) which says that properties and relations do exist, but that they are particulars rather than universals. | |
From: David M. Armstrong (Universals [1995], p.504) | |
A reaction: Both this view and the 'mereological' view seem to be ducking the problem. If you have two red particulars and a green one, how do we manage to spot the odd one out? |
4445 | If properties and relations are particulars, there is still the problem of how to classify and group them [Armstrong] |
Full Idea: The view that properties exist, but are particulars rather than universals, is still left with the problem of classification. On what basis do we declare that different things have the same property? | |
From: David M. Armstrong (Universals [1995], p.504) | |
A reaction: This seems like a fairly crucial objection. The original problem was how we manage to classify things (group them into sets), and it looks as if this theory leaves the problem untouched. |
4448 | Should we decide which universals exist a priori (through words), or a posteriori (through science)? [Armstrong] |
Full Idea: Should we decide what universals exist a priori (probably on semantic grounds, identifying them with the meanings of general words), or a posteriori (looking to our best general theories about nature to give revisable conjectures about universals)? | |
From: David M. Armstrong (Universals [1995], p.505) | |
A reaction: Nice question for a realist. Although the problem is first perceived in the use of language, if we think universals are a real feature of nature, we should pursue them scientifically, say I. |
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) |
4446 | It is claimed that some universals are not exemplified by any particular, so must exist separately [Armstrong] |
Full Idea: There are some who claim that there can be uninstantiated universals, which are not exemplified by any particular, past, present or future; this would certainly imply that those universals have a Platonic transcendent existence outside time and space. | |
From: David M. Armstrong (Universals [1995], p.504) | |
A reaction: Presumably this is potentially circular or defeasible, because one can deny the universal simply because there is no particular. |
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) |
4439 | 'Resemblance Nominalism' says properties are resemblances between classes of particulars [Armstrong] |
Full Idea: Resemblance Nominalists say that to have a property is to be a member of a class which is part of a network of resemblance relations with other classes of particulars. ..'Resemblance' is taken to be a primitive notion, though one that admits of degrees. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: Intuition suggests that this proposal has good prospects, as properties are neither identical, nor just particulars, but have a lot in common, which 'resemblance' captures. Hume saw resemblance as a 'primitive' process. |
4440 | 'Resemblance Nominalism' finds that in practice the construction of resemblance classes is hard [Armstrong] |
Full Idea: It is difficult for Resemblance Nominalists to construct their interconnected classes in practice. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: Given the complexity of the world this is hardly surprising, but it doesn't seem insuperable for the theory. It is hard to decide whether an object is white, or hot, whatever your theory of universals. |
4431 | 'Predicate Nominalism' says that a 'universal' property is just a predicate applied to lots of things [Armstrong] |
Full Idea: For a Predicate Nominalist different things have the same property, or belong to the same kind, if the same predicates applies to, or is 'true of', the different things. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: This immediately strikes me as unlikely, because I think the action is at the proposition level, not the sentence level. And why do some predicates seem to be synonymous? |
4433 | Concept and predicate nominalism miss out some predicates, and may be viciously regressive [Armstrong] |
Full Idea: The standard objections to Predicate and Concept Nominalism are that some properties have no predicates or concepts, and that predicates and concepts seem to be types rather than particulars, and it is types the theory is seeking to analyse. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: The claim that some properties have no concepts is devastating if true, but may not be. The regress problem is likely to occur in any explanation of universals, I suspect. |
4432 | 'Concept Nominalism' says a 'universal' property is just a mental concept applied to lots of things [Armstrong] |
Full Idea: Concept Nominalism says different things have the same property, or belong to the same kind, if the same concept in the mind is applied to different things. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: This is more appealing than Predicate Nominalism, and may be right. Our perception of the 'properties' of a thing may be entirely dictated by human interests, not by nature. |
4436 | 'Class Nominalism' may explain properties if we stick to 'natural' sets, and ignore random ones [Armstrong] |
Full Idea: Class Nominalism can be defended (by Quinton) against the problem of random sets (with nothing in common), by giving an account of properties in terms of 'natural' classes, where 'natural' comes in degrees, but is fundamental and unanalysable. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: This still seems to beg the question, because you still have to decide whether two things have anything 'naturally' in common before you assign them to a set. |
4435 | 'Class Nominalism' cannot explain co-extensive properties, or sets with random members [Armstrong] |
Full Idea: Class Nominalism cannot explain co-extensive properties (which qualify the same things), and also a random (non-natural) set has particulars with nothing in common, thus failing to capture an essential feature of a general property. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: These objections strike me as conclusive, since we can assign things to a set quite arbitrarily, so membership of a set may signify no shared property at all (except, say, 'owned by me', which is hardly a property). |
4434 | 'Class Nominalism' says that properties or kinds are merely membership of a set (e.g. of white things) [Armstrong] |
Full Idea: Class Nominalists substitute classes or sets for properties or kinds, so that being white is just being a member of the set of white things; relations are treated as ordered sets. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: This immediately seems wrong, because it invites the question of why something is a member of a set (unless membership is arbitrary and whimsical - which it usually isn't). |
4437 | 'Mereological Nominalism' sees whiteness as a huge white object consisting of all the white things [Armstrong] |
Full Idea: Mereological Nominalism views a property as the omnitemporal whole or aggregate of all the things said to have the property, so whiteness is a huge white object whose parts are all the white things. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: A charming proposal, in which bizarre and beautiful unities thread themselves across the universe, but white objects may also be soft and warm. |
4438 | 'Mereological Nominalism' may work for whiteness, but it doesn't seem to work for squareness [Armstrong] |
Full Idea: Mereological Nominalism has some plausibility for a case like whiteness, but breaks down completely for other universals, such as squareness. | |
From: David M. Armstrong (Universals [1995], p.503) | |
A reaction: A delightful request that you attempt a hopeless feat of imagination, by seeing all squares as parts of one supreme square. A nice objection. |
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) |
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. |
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) |
14303 | Truth-functional conditionals have a simple falsification, when A is true and B is false [Peirce] |
Full Idea: The utility of [truth-functional conditionals] is that it puts us in possession of a rule...[namely] The hypothetical proposition may be ...falsified by a single state of things, but only by one in which A [antecedent] is true and B [consequent] is false. | |
From: Charles Sanders Peirce (On the Algebra of Logic [1895], p.218), quoted by Stephen Mumford - Dispositions | |
A reaction: Personally I am rather more interested in verifying conditionals than in falsifying them. I certainly don't accept them until they are falsified, unless they have massive support from surrounding facts. |
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. |
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. |
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. |
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) |
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…. |
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-) |
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. |
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) |
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. |
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) |
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. |
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. |
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) |
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. |
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. |
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) |
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. |
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. |
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! |
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. |
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) |
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. |
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) |
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. |
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. |
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). |
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) |