49 ideas
| 9108 | From an impossibility anything follows [William of Ockham] |
| Full Idea: From an impossibility anything follows ('quod ex impossibili sequitur quodlibet'). | |
| From: William of Ockham (Summa totius logicae [1323], III.c.xxxvi) | |
| A reaction: The hallmark of a true logician, I suspect, is that this opinion is really meaningful and important to them. They yearn to follow the logic wherever it leads. Common sense would seem to say that absolutely nothing follows from an impossibility. |
| 16676 | Why use more things when fewer will do? [William of Ockham] |
| Full Idea: It is pointless to do through more things something that can be done through fewer. | |
| From: William of Ockham (Tractatus de corpore Christi [1323], Ch. 29), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 14.3 | |
| A reaction: The more famous formulation isn't found in his works, so I'm delighted to find an authentic quotation from the man. |
| 6806 | Do not multiply entities beyond necessity [William of Ockham] |
| Full Idea: Do not multiply entities beyond necessity. | |
| From: William of Ockham (works [1335]) | |
| A reaction: This is the classic statement of Ockham's Razor, though it is not found in his printed works. It appears to be mainly aimed at Plato's Theory of Forms. It is taken to refer to types of entities, not numbers. One seraph is as bad as a hundred. |
| 9107 | A proposition is true if its subject and predicate stand for the same thing [William of Ockham] |
| Full Idea: If in the proposition 'This is an angel' subject and predicate stand for the same thing, the proposition is true. | |
| From: William of Ockham (Summa totius logicae [1323], II.c.ii) | |
| A reaction: An interesting statement of what looks like a correspondence theory, employing the idea that both the subject and the predicate have a reference. I think Frege would say that 'x is an angel' is unsaturated, and so lacks reference. |
| 16300 | Ockham had an early axiomatic account of truth [William of Ockham, by Halbach] |
| Full Idea: Theories structurally very similar to axiomatic compositional theories of truth can be found in Ockham's 'Summa Logicae'. | |
| From: report of William of Ockham (Summa totius logicae [1323]) by Volker Halbach - Axiomatic Theories of Truth 3 |
| 9106 | The word 'every' only signifies when added to a term such as 'man', referring to all men [William of Ockham] |
| Full Idea: The syncategorematic word 'every' does not signify any fixed thing, but when added to 'man' it makes the term 'man' stand for all men actually. | |
| From: William of Ockham (Summa totius logicae [1323], I.c.iv) | |
| A reaction: Although quantifiers may have become a part of formal logic with Frege, their importance is seen from Aristotle onwards, and it is clearly a key part of William's understanding of logic. |
| 9113 | Just as unity is not a property of a single thing, so numbers are not properties of many things [William of Ockham] |
| Full Idea: Number is nothing but the actual numbered things themselves. Hence just as unity is not an accident added to the thing which is one, so number is not an accident of the things which are numbered. | |
| From: William of Ockham (Summa totius logicae [1323], I.c.xliv) | |
| A reaction: [William does not necessarily agree with this view] It strikes me as a key point here that any account of the numbers had better work for 'one', though 'zero' might be treated differently. Some people seem to think unity is a property of things. |
| 9110 | The words 'thing' and 'to be' assert the same idea, as a noun and as a verb [William of Ockham] |
| Full Idea: The words 'thing' and 'to be' (esse) signify one and the same thing, but the one in the manner of a noun and the other in the manner of a verb. | |
| From: William of Ockham (Summa totius logicae [1323], III,II,c,xxvii) | |
| A reaction: Well said - as you would expect from a thoroughgoing nominalist. I would have thought that this was the last word on the subject of Being, thus rendering any need for me to read Heidegger quite superfluous. Or am I missing something? |
| 16608 | Ockham was an anti-realist about the categories [William of Ockham, by Pasnau] |
| Full Idea: Ockham is the scholastic paradigm of anti-realism with respect to the categories. | |
| From: report of William of Ockham (Summula philosophiae naturalis [1320]) by Robert Pasnau - Metaphysical Themes 1274-1671 05.3 | |
| A reaction: These are the ten categories mentioned in Aristotle's book 'Categories'. |
| 16654 | Our words and concepts don't always correspond to what is out there [William of Ockham] |
| Full Idea: It should not be said that as distinct words and intentions or concepts are distinct from one another, so too the corresponding things are distinct. Those distinctions do not always line up with distinctions among things that are signified. | |
| From: William of Ockham (Predest.,God's foreknowledge and contingents [1320], 7.1), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 12.2 | |
| A reaction: [compressed] This is the great nominalist opponent of the idea that Aristotle's ten categories give an accurate map of reality. He proposed just substance and accidents, and based categorisation on the questions we ask. |
| 18529 | Relations are expressed either as absolute facts, or by a relational concept [William of Ockham] |
| Full Idea: Socrates and Plato are similar if they are both white. Yet the mind can express this either by an 'absolute concept' (as 'Socrates is white' and 'Plato is white'), or by a 'relative concept', as 'Socrates is similar to Plato with respect to whiteness. | |
| From: William of Ockham (Seven Quodlibets [1332], VI q.25), quoted by John Heil - The Universe as We Find It 7 | |
| A reaction: Presumably he takes the facts of the matter to be the absolute concept, and the relative concept to be a contribution of the intellect. |
| 22132 | Species and genera are individual concepts which naturally signify many individuals [William of Ockham] |
| Full Idea: In his mature nominalism, species and genera are identified with certain mental qualities called concepts or intentions of the mind. Ontologically they are individuals too, like everthing else, ...but they naturally signify many different individuals. | |
| From: William of Ockham (works [1335]), quoted by Claude Panaccio - William of Ockham p.1056 | |
| A reaction: 'Naturally' is the key word, because the concepts are not fictions, but natural responses to encountering individuals in the world. I am an Ockhamist. |
| 9103 | A universal is not a real feature of objects, but only a thought-object in the mind [William of Ockham] |
| Full Idea: I maintain that a universal is not something real that exists in a subject [of inherence], either inside or outside the mind, but that it has being only as a thought-object in the mind. | |
| From: William of Ockham (Ordinatio [1320], DII Qviii prima redactio) | |
| A reaction: [A footnote says that William later abandoned this view] I don't see a clear distinction here between having real existence in the mind, and being a thought-object in the mind. Maybe we should say 'merely' a thought-object? |
| 15388 | Universals are single things, and only universal in what they signify [William of Ockham] |
| Full Idea: Every universal is one particular thing and it is not a universal except in its signification, in its signifying many thing. | |
| From: William of Ockham (Summa totius logicae [1323]), quoted by Claude Panaccio - Medieval Problem of Universals 'William' | |
| A reaction: Sounds as if William might have liked tropes. It seems to leave the problem unanswered (the 'ostrich' problem?). How are they able to signify in this universal way, if each thing is just distinct and particular? |
| 16779 | Cut wood doesn't make a new substance, but seems to make separate subjects [William of Ockham] |
| Full Idea: When a piece of wood is divided in two halves, no new substance is generated. But there are now two substances, or the accidents of the two halves would be without a subject. They existed before hand, and were one piece of wood, but not in the same place. | |
| From: William of Ockham (Seven Quodlibets [1332], IV.19), quoted by Richard S. Westfall - Never at Rest: a biography of Isaac Newton 26.2 | |
| A reaction: A nice example, demonstrating that there are substances within substances, contrary to the view of Duns Scotus. If a substance is just a subject for properties, it is hard to know what to make of this case. |
| 16757 | Hot water naturally cools down, which is due to the substantial form of the water [William of Ockham] |
| Full Idea: It is clear to the senses that hot water, if left to its own nature, reverts to coldness; this coldness cannot be caused by anything other than the substantial form of the water. | |
| From: William of Ockham (Seven Quodlibets [1332], III.6), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 24.4 | |
| A reaction: Unfortunately this is very bad science (even for its time), but it shows how many scholastics treated hylomorphism as a very physical and causal theory. |
| 16599 | Ockham says matter must be extended, so we don't need Quantity [William of Ockham, by Pasnau] |
| Full Idea: Ockham regards Quantity as an entirely superfluous ontological category, …because matter is intrinsically extended. | |
| From: report of William of Ockham (Summula philosophiae naturalis [1320]) by Robert Pasnau - Metaphysical Themes 1274-1671 04.4 |
| 16681 | Matter gets its quantity from condensation and rarefaction, which is just local motion [William of Ockham] |
| Full Idea: Matter is made to have a greater or lesser quantity not through its receiving any absolute accident, but through condensation and rarefaction alone. Parts come more or less close together, which can happen with local motion. | |
| From: William of Ockham (Summula philosophiae naturalis [1320], I.13), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 15.1 | |
| A reaction: This is Ockham at his most modern, rejecting the odd idea of Quantity in favour of a modern corpuscular view of the mere motions of matter. |
| 9109 | If essence and existence were two things, one could exist without the other, which is impossible [William of Ockham] |
| Full Idea: If essence and existence were two things, then no contradiction would be involved if God preserved the essence of a thing in the world without its existence, or vice versa, its existence without its essence; both of which are impossible. | |
| From: William of Ockham (Summa totius logicae [1323], III,II,c,xxvii) | |
| A reaction: Not that William is using the concept of a supreme mind as a tool in argument. His denial of essence as something separable is presumably his denial of the Aristotelian view of universals, as well as of the Platonic view. |
| 16792 | If parts change, the whole changes [William of Ockham] |
| Full Idea: That is not the same whole that does not have the same parts. | |
| From: William of Ockham (Commentary on the Sentences [1320], IV.13), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 29.2 | |
| A reaction: In isolation, this is mereological essentialism (as Pasnau confirms), which is incredibly implausible, if I cease to be the same person when I cut one of my fingernails. |
| 9089 | Knowledge is a quality existing subjectively in the soul [William of Ockham] |
| Full Idea: Knowledge is a certain quality which exists in the soul as its subject ('existens subiective in anima'). | |
| From: William of Ockham (Expositio super viii libros [1340], Prologue) | |
| A reaction: One might say here that knowledge is a property, and so it might not be susceptible to further analysis. It invites the question of how you could know by introspection that you have got it, which would be an extreme internalist view. |
| 9091 | Sometimes 'knowledge' just concerns the conclusion, sometimes the whole demonstration [William of Ockham] |
| Full Idea: Sometimes 'knowledge' means evident cognition of the conclusion alone, sometimes of the demonstration as a whole. | |
| From: William of Ockham (Expositio super viii libros [1340], Prologue) | |
| A reaction: 'Demonstration' will be something like Greek 'logos' - full understanding, ability to explain and give reasons. William is certainly right about normal usage. I know the answer in a quiz, without any requirement for justifications. |
| 9100 | Our intellect only assents to what we believe to be true [William of Ockham] |
| Full Idea: Our intellect does not assent to anything unless we believe it to be true. | |
| From: William of Ockham (Prologue to Ordinatio [1320], Q 1 N sqq) | |
| A reaction: This strikes me as being a much more accurate and commonsense view of belief than that of Hume, who simply views it phenomenologically. ...But then the remark appears to be circular. Belief requires a belief that it is true. Hm. |
| 9090 | Knowledge is certain cognition of something that is true [William of Ockham] |
| Full Idea: Knowledge is certain cognition of something that is true. | |
| From: William of Ockham (Expositio super viii libros [1340], Prologue) | |
| A reaction: This view has problems. William is not facing up to the sceptical questions which can shake any degree of certainty, and also that someone who lacked self-confidence might know many things while always feeling uncertain about them. 'Cognition' must go! |
| 9101 | Abstractive cognition knows universals abstracted from many singulars [William of Ockham] |
| Full Idea: Abstractive cognition (in one sense) relates to something abstracted from many singulars; and in this sense abstractive cognition is nothing else but cognition of a universal which can be abstracted from many things. | |
| From: William of Ockham (Prologue to Ordinatio [1320], Q 1 N sqq) | |
| A reaction: This strikes me as being correct common sense, even though it has become deeply unfashionable since Frege. We may not be able to see quite how the mind manages to see universals in a bunch of objects, but there is no better story. |
| 9102 | If an animal approached from a distance, we might abstract 'animal' from one instance [William of Ockham] |
| Full Idea: It seems possible that the concept of a genus could be abstracted from one individual, let us say, the concept 'animal', as in the case of one approaching from a distance, when I see enough to judge that I am seeing an animal. | |
| From: William of Ockham (Seven Quodlibets [1332], I Q xiii) | |
| A reaction: This is a rather individualistic view of abstraction, ignoring the shared language and culture. It is hard to imagine a truly virgin mind coming up with the concept after one encounter. The concept 'mind-boggling' seems more likely. |
| 9114 | There are no secure foundations to prove the separate existence of mind, in reason or experience [William of Ockham] |
| Full Idea: The existence of an immaterial 'intellective soul' ..cannot be demonstrated; for every reason by which we try to prove it assumes something that is doubtful for a man who follows only his natural reason. Neither can it be proved by experience. | |
| From: William of Ockham (Seven Quodlibets [1332], I Q x) | |
| A reaction: This is splendid honesty from a medieval monk. How would such a clear thinker have responded to modern brain research? Colin McGinn still maintains William's view, despite modern knowledge. Our ignorance produced conceptual dualism. |
| 9104 | A universal is the result of abstraction, which is only a kind of mental picturing [William of Ockham] |
| Full Idea: A universal is not the result of generation, but of abstraction, which is only a kind of mental picturing. | |
| From: William of Ockham (Ordinatio [1320], DII Qviii prima redactio) | |
| A reaction: The phrase 'mental picturing' works very plausibly for the universal 'giraffe', but not so well for 'multiplication' or 'contradiction'. Though we might broaden 'picturing' to being a much less visual concept. Mapping seems basic. |
| 9105 | Some concepts for propositions exist only in the mind, and in no language [William of Ockham] |
| Full Idea: Conceptual terms and the propositions formed by them are those mental words which do not belong to any language; they remain only in the mind and cannot be uttered exteriorly, though signs subordinated to these can be exteriorly uttered. | |
| From: William of Ockham (Summa totius logicae [1323], I.c.i) | |
| A reaction: [He cites Augustine] A glimmer of the idea of Mentalese, and is probably an integral part of any commitment to propositions. Quine would hate it, but I like it. Logicians seem to dislike anything that cannot be articulated, but brains are like that. |
| 4761 | The 'error theory' of morals says there is no moral knowledge, because there are no moral facts [Mackie, by Engel] |
| Full Idea: Mackie's 'error theory' of ethics says that if a fact is something that corresponds to a true proposition, there are actually no moral facts, hence no knowledge of what moral statements are about. | |
| From: report of J.L. Mackie (Ethics: Inventing Right and Wrong [1977]) by Pascal Engel - Truth §4.2 | |
| A reaction: Personally I am inclined to think that there are moral facts (about what nature shows us constitutes a good human being), based on virtue theory. Mackie is a good warning, though, against making excessive claims. You end up like a bad scientist. |
| 6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |
| Full Idea: Hermarchus said that animal killing is justified by considerations of human safety and nourishment and by animals' inability to form contractual relations of justice with us. | |
| From: report of Hermarchus (fragments/reports [c.270 BCE]) by David A. Sedley - Hermarchus | |
| A reaction: Could the last argument be used to justify torturing animals? Or could we eat a human who was too brain-damaged to form contracts? |
| 16675 | Every extended material substance is composed of parts distant from one another [William of Ockham] |
| Full Idea: Every extended material substance is composed of substantial parts distant from one another in place or location. | |
| From: William of Ockham (Tractatus de corpore Christi [1323], Ch. 12) | |
| A reaction: Pasnau glosses this as that 'bodies have corpuscular structure', meaning that they are made up of parts of matter (rather than just enformed matter, I think). |
| 8337 | Some says mental causation is distinct because we can recognise single occurrences [Mackie] |
| Full Idea: It is sometimes suggested that our ability to recognise a single occurrence as an instance of mental causation is a feature which distinguishes mental causation from physical or 'Humean' causation. | |
| From: J.L. Mackie (Causes and Conditions [1965], §9) | |
| A reaction: Hume says regularities are needed for mental causation too. Concentrate hard on causing a lightning flash - 'did I do that?' Gradually recovering from paralysis; you wouldn't just move your leg once, and know it was all right! |
| 8342 | Mackie tries to analyse singular causal statements, but his entities are too vague for events [Kim on Mackie] |
| Full Idea: In spite of Mackie's announced aim of analysing singular causal statements, it is doubtful that the entities that he is concerned with can be consistently interpreted as spatio-temporally bounded individual events. | |
| From: comment on J.L. Mackie (Causes and Conditions [1965]) by Jaegwon Kim - Causes and Events: Mackie on causation §3 | |
| A reaction: This is because Mackie mainly talks about 'conditions'. Nearly every theory I encounter in modern philosophy gets accused of either circular definitions, or inadequate individuation conditions for key components. A tough world for theory-makers. |
| 8343 | Necessity and sufficiency are best suited to properties and generic events, not individual events [Kim on Mackie] |
| Full Idea: Relations of necessity and sufficiency seem best suited for properties and for property-like entities such as generic states and events; their application to individual events and states is best explained as derivative from properties and generic events. | |
| From: comment on J.L. Mackie (Causes and Conditions [1965]) by Jaegwon Kim - Causes and Events: Mackie on causation §4 | |
| A reaction: This seems to suggest that necessity must either derive from laws, or from powers. It is certainly hard to see how you could do Mackie's assessment of necessary and sufficient components, without comparing similar events. |
| 8385 | A cause is part of a wider set of conditions which suffices for its effect [Mackie, by Crane] |
| Full Idea: The details of Mackie's analysis are complex, but the general idea is that the cause is part of a wider set of conditions which suffices for its effect. | |
| From: report of J.L. Mackie (Causes and Conditions [1965]) by Tim Crane - Causation 1.3.3 | |
| A reaction: Helpful. Why does something have to be 'the' cause? Immediacy is a vital part of it. A house could be a 'fire waiting to happen'. Oxygen is an INUS condition for a fire. |
| 8335 | Necessary conditions are like counterfactuals, and sufficient conditions are like factual conditionals [Mackie] |
| Full Idea: A necessary causal condition is closely related to a counterfactual conditional: if no-cause then no-effect, and a sufficient causal condition is closely related to a factual conditional (Goodman's phrase): since cause-here then effect. | |
| From: J.L. Mackie (Causes and Conditions [1965], §4) | |
| A reaction: The 'factual conditional' just seems to be an assertion that causation occurred (dressed up with the logical-sounding 'since'). An important distinction for Lewis. Sufficiency doesn't seem to need possible-worlds talk. |
| 8336 | The INUS account interprets single events, and sequences, causally, without laws being known [Mackie] |
| Full Idea: My account shows how a singular causal statement can be interpreted, and how the corresponding sequence can be shown to be causal, even if the corresponding complete laws are not known. | |
| From: J.L. Mackie (Causes and Conditions [1965], §9) | |
| A reaction: Since the 'complete' laws are virtually never known, it would be a bit much to require that to assert causation. His theory is the 'INUS' account of causal conditions - see Idea 8333. |
| 8333 | A cause is an Insufficient but Necessary part of an Unnecessary but Sufficient condition [Mackie] |
| Full Idea: If a short-circuit causes a fire, the so-called cause is, and is known to be, an Insufficient but Necessary part of a condition which is itself Unnecessary but Sufficient for the result. Let us call this an INUS condition. | |
| From: J.L. Mackie (Causes and Conditions [1965], §1) | |
| A reaction: I'm not clear why it is necessary, given that the fire could have started without the short-circuit. The final situation must certainly be sufficient. If only one situation can cause an effect, then the whole situation is necessary. |
| 8395 | Mackie has a nomological account of general causes, and a subjunctive conditional account of single ones [Mackie, by Tooley] |
| Full Idea: For general causal statements Mackie favours a nomological account, but for singular causal statements he argued for an analysis in terms of subjunctive conditionals. | |
| From: report of J.L. Mackie (Causes and Conditions [1965]) by Michael Tooley - Causation and Supervenience 5.2 | |
| A reaction: These seem to be consistent, by explaining each by placing it within a broader account of reality. Personally I think Ducasse gives the best account of how you get from the particular to the general (via similarity and utility). |
| 8334 | The virus causes yellow fever, and is 'the' cause; sweets cause tooth decay, but they are not 'the' cause [Mackie] |
| Full Idea: We may say not merely that this virus causes yellow fever, but also that it is 'the' cause of yellow fever; but we could only say that sweet-eating causes dental decay, not that it is the cause of dental decay (except in an individual case). | |
| From: J.L. Mackie (Causes and Conditions [1965], §3) | |
| A reaction: A bit confusing, but there seems to be something important here, concerning the relation between singular causation and law-governed causation. 'The' cause may not be sufficient (I'm immune to yellow fever). So 'the' cause is the only necessary one? |
| 19381 | The past has ceased to exist, and the future does not yet exist, so time does not exist [William of Ockham] |
| Full Idea: Time is composed of non-entities, because it is composed of the past which does not exist now, although it did exist, and of the future, which does not yet exist; therefore time does not exist. | |
| From: William of Ockham (works [1335], 6:496), quoted by Richard T.W. Arthur - Leibniz 7 'Nominalist' | |
| A reaction: I've a lot of sympathy with this! I favour Presentism, so the past is gone and the future is yet to arrive. But we have no coherent concept of a present moment of any duration to contain reality. We are just completely bogglificated by it all. |
| 9111 | God is not wise, but more-than-wise; God is not good, but more-than-good [William of Ockham] |
| Full Idea: God is not wise, but more-than-wise; God is not good, but more-than-good. | |
| From: William of Ockham (Reportatio [1330], III Q viii) | |
| A reaction: [He is quoting 'Damascene'] I quote this for interest, but I very much doubt whether Damascene or William knew what it meant, and I certainly don't. There seems to have been a politically correct desire to invent super-powers for God. |
| 8010 | William of Ockham is the main spokesman for God's commands being the source of morality [William of Ockham] |
| Full Idea: The most notable philosopher who makes God's commandment the basis of goodness, rather than God's goodness a reason for obeying him, is William of Occam. | |
| From: William of Ockham (works [1335]), quoted by Alasdair MacIntyre - A Short History of Ethics Ch.9 | |
| A reaction: Either view has problems. Why choose God to obey? Obey anyone who is powerful? But how do you decide that God is good? How do we know the nature of God's commands, or the nature of God's goodness? Etc. |
| 9112 | We could never form a concept of God's wisdom if we couldn't abstract it from creatures [William of Ockham] |
| Full Idea: What we abstract is said to belong to perfection in so far as it can be predicated of God and can stand for Him. For if such a concept could not be abstracted from a creature, then in this life we could not arrive at a cognition of God's wisdom. | |
| From: William of Ockham (Reportatio [1330], III Q viii) | |
| A reaction: This seems to be the germ of an important argument. Without the ability to abstract from what is experienced, we would not be able to apply general concepts to things which are beyond experience. It is a key idea for empiricism. |
| 9115 | To love God means to love whatever God wills to be loved [William of Ockham] |
| Full Idea: To love God above all means to love whatever God wills to be loved. | |
| From: William of Ockham (Seven Quodlibets [1332], III Q xiii) | |
| A reaction: A striking thought, which could be meaningful to the non-religious. Is it possible to form an image of what a perfect and ideal mind would love most? This might generate a set of universal values. It is tricky to find out what an actual God loves. |
| 16679 | Even an angel must have some location [William of Ockham, by Pasnau] |
| Full Idea: Ockham dismisses the possibility of non-location out of hand, remarking that even an angel has some location. | |
| From: report of William of Ockham (works [1335]) by Robert Pasnau - Metaphysical Themes 1274-1671 14.4 |
| 1473 | Is evil an illusion, or a necessary contrast, or uncontrollable, or necessary for human free will? [Mackie, by PG] |
| Full Idea: Perhaps evil is an illusion, or it is necessary for good to exist, or in humans it is required because we have free will, or God lacks the full power to control it, but none of these looks convincing. | |
| From: report of J.L. Mackie (Evil and Omnipotence [1955], §B) by PG - Db (ideas) |
| 1472 | The propositions that God is good and omnipotent, and that evil exists, are logically contradictory [Mackie, by PG] |
| Full Idea: There is a contradiction between the propositions that God is wholly good, God is omnipotent, and evil exists, and one of them has got to give way (assuming good eliminates evil, and omnipotence has no limit). | |
| From: report of J.L. Mackie (Evil and Omnipotence [1955], Pref.) by PG - Db (ideas) |