64 ideas
24047 | An account is either a definition or a demonstration [Aristotle] |
Full Idea: Every account is either a definition or a demonstration. | |
From: Aristotle (De Anima [c.329 BCE], 407a24) | |
A reaction: That is, it is either a summary of the thing's essential nature, or it is a proof of some natural fact, starting from first principles. |
24052 | From one thing alone we can infer its contrary [Aristotle] |
Full Idea: One member of a pair of contraries is sufficient to discern both itself and its opposite. | |
From: Aristotle (De Anima [c.329 BCE], 411a02) | |
A reaction: This obviously requires prior knowledge of what the opposite is. He says you can infer the crooked from the straight. You can hardly use light in isolation to infer dark [see DA 418b17]. What's the opposite of a pig? |
16951 | It was realised that possible worlds covered all modal logics, if they had a structure [Dummett] |
Full Idea: The new discovery was that with a suitable structure imposed on the space of possible worlds, the Leibnizian idea would work for all modal logics. | |
From: Michael Dummett (Could There Be Unicorns? [1983], 1) |
16952 | If something is only possible relative to another possibility, the possibility relation is not transitive [Dummett] |
Full Idea: If T is only possible if S obtains, and S is possible but doesn't obtain, then T is only possible in the world where S obtains, but T is not possible in the actual world. It follows that the relation of relative possibility is not transitive. | |
From: Michael Dummett (Could There Be Unicorns? [1983], 1) | |
A reaction: [compressed] |
16953 | Relative possibility one way may be impossible coming back, so it isn't symmetrical [Dummett] |
Full Idea: If T is only possible if S obtains, T and S hold in the actual world, and S does not obtain in world v possible relative to the actual world, then the actual is not possible relative to v, since T holds in the actual. Accessibility can't be symmetrical. | |
From: Michael Dummett (Could There Be Unicorns? [1983], 1) |
16960 | If possibilitiy is relative, that might make accessibility non-transitive, and T the correct system [Dummett] |
Full Idea: If some world is 'a way the world might be considered to be if things were different in a certain respect', that might show that the accessibility relation should not be taken to be transitive, and we should have to adopt modal logic T. | |
From: Michael Dummett (Could There Be Unicorns? [1983], 8) | |
A reaction: He has already rejected symmetry from the relation, for reasons concerning relative identity. He is torn between T and S4, but rejects S5, and opts not to discuss it. |
16958 | In S4 the actual world has a special place [Dummett] |
Full Idea: In S4 logic the actual world is, in itself, special, not just from our point of view. | |
From: Michael Dummett (Could There Be Unicorns? [1983], 8) | |
A reaction: S4 lacks symmetricality, so 'you can get there, but you can't get back', which makes the starting point special. So if you think the actual world has a special place in modal metaphysics, you must reject S5? |
1729 | We perceive number by the denial of continuity [Aristotle] |
Full Idea: Number we perceive by the denial of continuity. | |
From: Aristotle (De Anima [c.329 BCE], 425a19) | |
A reaction: This is a key thought. A being (call it 'Parmenides') which sees all Being as One would make no distinctions of identity, and so could not count anything. Why would they want numbers? |
24057 | What is prior is always potentially present in what is next in order [Aristotle] |
Full Idea: What is prior is always potentially present in what is next in order … - for example, the triangle in the quadrilateral, or the nutritive part of animate things in the perceptual part. | |
From: Aristotle (De Anima [c.329 BCE], 414a28) | |
A reaction: 'Prior' seems to be a value for Aristotle, which is never present in modern discussions of ontological relations and structure. Priority tracks back to first principles. |
16752 | Sight is the essence of the eye, fitting its definition; the eye itself is just the matter [Aristotle] |
Full Idea: If the eye were an animal, sight would have been its soul, for sight is the substance or essence of the eye which corresponds to the formula, the eye being merely the matter of seeing; when seeing is removed it is no longer an eye,except in name. | |
From: Aristotle (De Anima [c.329 BCE], 412b18) | |
A reaction: This is a drastic view of form as merely function, which occasionally appears in Aristotle. To say a blind eye is not an eye is a tricky move in metaphysics. So what is it? In some sense it is still an eye. |
24058 | The substance is the cause of a thing's being [Aristotle] |
Full Idea: The cause of its being for everything is its substance. | |
From: Aristotle (De Anima [c.329 BCE], 415b12) | |
A reaction: It sounds as if 'substance' here means essence. We no longer see the cause of something's being as intrinsic to the thing. Only previous causes produce things. The 'form' must be the intrinsic cause of being. |
24055 | Matter is potential, form is actual [Aristotle] |
Full Idea: Matter is potentiality, whereas form is actuality. | |
From: Aristotle (De Anima [c.329 BCE], 412a09) | |
A reaction: Plato said mud has no Form. What did Aristotle think of that? I only ask because to me mud looks like unformed actuality. |
24040 | Scientists explain anger by the matter, dialecticians by the form and the account [Aristotle] |
Full Idea: For a dialectician anger is a desire for retaliation or something like that, where for a natural scientist it is a boiling of the blood and hoot stuff around the heart. The scientist gives the matter, where the dialectician give the form and the account. | |
From: Aristotle (De Anima [c.329 BCE], 403a30) | |
A reaction: A nice illumination of hylomorphism. Notice that the dialectician also give the account [logos]. |
16957 | Possible worlds aren't how the world might be, but how a world might be, given some possibility [Dummett] |
Full Idea: The equation of a possible world with the way that the (actual) world might be is wrong: the way a distant world might be is not a way the world might be, but a way we might allow it to be given how some intervening world might be. | |
From: Michael Dummett (Could There Be Unicorns? [1983], 8) | |
A reaction: The point here is that a system of possible worlds must include relative possibilities as well as actual possibilities. Dummett argues against S5 modal logic, which makes them all equal. Things impossible here might become possible. Nice. |
16959 | If possible worlds have no structure (S5) they are equal, and it is hard to deny them reality [Dummett] |
Full Idea: If our space of possible worlds has no structure, as in the semantics for S5, then, from the standpoint of the semantics, all possible worlds are on the same footing; it then becomes difficult to resist the claim that all are equally real. | |
From: Michael Dummett (Could There Be Unicorns? [1983], 8) | |
A reaction: This is a rather startling and interesting claim, given that modern philosophy seems full of thinkers who both espouse S5 for metaphysics, and also deny Lewisian realism about possible worlds. I'll ponder that one. Must read the new Williamson…. |
5051 | The intellect has potential to think, like a tablet on which nothing has yet been written [Aristotle] |
Full Idea: The intellect is in a way potentially the object of thought, but nothing in actuality before it thinks, and the potentiality is like that of the tablet on which there is nothing actually written. | |
From: Aristotle (De Anima [c.329 BCE], 429b31) | |
A reaction: This passage is referred to by Leibniz, and is the origin of the concept of the 'tabula rasa'. Aristotle need not be denying innate ideas, but merely describing the phenomenology of the moment before a train of thought begins. |
16723 | Perception of sensible objects is virtually never wrong [Aristotle] |
Full Idea: Perception of the special objects of sense is never in error or admits the least possible amount of falsehood. | |
From: Aristotle (De Anima [c.329 BCE], 428b19) | |
A reaction: This is, surprisingly, the view which was raised and largely rejected in 'Theaetetus'. It became a doctrine of Epicureanism, and seems to make Aristotle a thoroughgoing empiricist, though that is not so clear elsewhere. I think Aristotle is right. |
1724 | Perception necessitates pleasure and pain, which necessitates appetite [Aristotle] |
Full Idea: Where there is perception there is also pleasure and pain, and where there are these, of necessity also appetite. | |
From: Aristotle (De Anima [c.329 BCE], 413b23) |
1730 | Why do we have many senses, and not just one? [Aristotle] |
Full Idea: A possible line of inquiry would be into the question for what purpose we have many senses and not just one. | |
From: Aristotle (De Anima [c.329 BCE], 425b04) |
17711 | Our minds take on the form of what is being perceived [Aristotle, by Mares] |
Full Idea: Aristotle famously holds that in perception our minds take on the form of what is being perceived. | |
From: report of Aristotle (De Anima [c.329 BCE]) by Edwin D. Mares - A Priori 08.2 | |
A reaction: [References in Aristotle needed here...] |
1732 | Sense organs aren't the end of sensation, or they would know what does the sensing [Aristotle] |
Full Idea: Flesh is not the ultimate sense-organ. To suppose that it is requires the supposition that on contact with the object the sense-organ itself discerns what is doing the discerning. | |
From: Aristotle (De Anima [c.329 BCE], 426b16) |
1725 | Why can't we sense the senses? And why do senses need stimuli? [Aristotle] |
Full Idea: Why is there not also a sense of the senses themselves? And why don't the senses produce sensation without external bodies, since they contain elements? | |
From: Aristotle (De Anima [c.329 BCE], 417a03) |
1728 | Many objects of sensation are common to all the senses [Aristotle] |
Full Idea: Common sense-objects are movement, rest, number, shape and size, which are not special to any one sense, but common to all. | |
From: Aristotle (De Anima [c.329 BCE], 418a18) |
1727 | Some objects of sensation are unique to one sense, where deception is impossible [Aristotle] |
Full Idea: Now I call that sense-object 'special' that does not admit of being perceived by another sense and about which it is impossible to be deceived. | |
From: Aristotle (De Anima [c.329 BCE], 418a15) |
1734 | In moral thought images are essential, to be pursued or avoided [Aristotle] |
Full Idea: In the thinking soul, images play the part of percepts, and the assertion or negation of good or bad is invariably accompanied by avoidance or pursuit, which is the reason for the soul's never thinking without an image. | |
From: Aristotle (De Anima [c.329 BCE], 431a15) |
1726 | We may think when we wish, but not perceive, because universals are within the mind [Aristotle] |
Full Idea: Perception is of particular things, but knowledge is of universals, which are in a way in the soul itself. Thus a man may think whenever he wishes, but not perceive. | |
From: Aristotle (De Anima [c.329 BCE], 417b22) |
16647 | Demonstration starts from a definition of essence, so we can derive (or conjecture about) the properties [Aristotle] |
Full Idea: In demonstration a definition of the essence is required as starting point, so that definitions which do not enable us to discover the derived properties, or which fail to facilitate even a conjecture about them, must obviously be dialectical and futile. | |
From: Aristotle (De Anima [c.329 BCE], 402b25) | |
A reaction: Interesting to see 'dialectical' used as a term of abuse! Illuminating. For scientific essentialism, then, demonstration is filling out the whole story once the essence has been inferred. It is circular, because essence is inferred from accidents. |
24048 | Demonstrations move from starting-points to deduced conclusions [Aristotle] |
Full Idea: Demonstrations are both from a starting-point and have a sort of end, namely the deduction or the conclusion. | |
From: Aristotle (De Anima [c.329 BCE], 407a25) | |
A reaction: A starting point has to be a first principle [arché]. It has been observed that Aristotle explains demonstration very carefully, but rarely does it in his writings. |
16646 | To understand a triangle summing to two right angles, we need to know the essence of a line [Aristotle] |
Full Idea: In mathematics it is useful for the understanding of the property of the equality of the interior angles of a triangle to two right angles to know the essential nature of the straight and the curved or of the line and the plane. | |
From: Aristotle (De Anima [c.329 BCE], 402b18) | |
A reaction: Although Aristotle was cautious about this, he clearly endorses here the idea that essences play an explanatory role in geometry. The caution is in the word 'useful', rather than 'vital'. How else can we arrive at this result, though? |
1714 | Mind involves movement, perception, incorporeality [Aristotle] |
Full Idea: The soul seems to be universally defined by three features, so to speak, the production of movement, perception and incorporeality. | |
From: Aristotle (De Anima [c.329 BCE], 405b12) | |
A reaction: 'Incorporeality' begs the question, but its appearance is a phenomenon that needs explaining. 'Movement' is an interesting Greek view. Nowadays we would presumably added intentional states, and the contents and meaning of thoughts. No 'reason'? |
5507 | Aristotle led to the view that there are several souls, all somewhat physical [Aristotle, by Martin/Barresi] |
Full Idea: On the later views inspired by Aristotle's 'De Anima' there was no longer just one soul, but several, and each of them had a great deal in common with the body. | |
From: report of Aristotle (De Anima [c.329 BCE]) by R Martin / J Barresi - Introduction to 'Personal Identity' p.17 | |
A reaction: Is this based on the faculties of sophia, episteme, nous, techne and phronesis, or is it based on the vegetative, appetitive and rational parts? The latter, I presume. Not so interesting, not so modular. |
24051 | Soul is seen as what moves, or what is least physical, or a combination of elements [Aristotle] |
Full Idea: Three ways have been handed down in which people define the soul: what is most capable of moving things, since it moves itself; or a body which is the most fine-grained and least corporeal; or that it is composed of the elements. | |
From: Aristotle (De Anima [c.329 BCE], 409b19) | |
A reaction: A nice example of Aristotle beginning an investigation by idenfying the main explanations which have been 'handed down' from previous generations. These three aren't really in competition, and might all be true. |
12086 | Psuché is the form and actuality of a body which potentially has life [Aristotle] |
Full Idea: Soul is substance as the form of a natural body which potentially has life, and since this substance is actuality, soul will be the actuality of such a body. | |
From: Aristotle (De Anima [c.329 BCE], 412a20) | |
A reaction: To understand what Aristotle means by 'form' you must, I'm afraid, read the 'Metaphysics'. Form isn't shape, but rather the essence which bestows the individual identity on the thing. 'Psuche is the essence of man' might be a better slogan. |
16754 | The soul is the cause or source of movement, the essence of body, and its end [Aristotle] |
Full Idea: The soul is the cause [aitia] of its body alike in three senses which we explicitly recognise. It is (a) the source or origin of movement, it is (b) the end, and it is (c) the essence of the whole living body. | |
From: Aristotle (De Anima [c.329 BCE], 415b09) | |
A reaction: 'Aitia' also means explanation, so these are three ways to explain a human being, by what it does, why what it is for, and by what it intrinsically is. Activity, purpose and nature. |
24046 | Understanding is impossible, if it involves the understanding having parts [Aristotle] |
Full Idea: How could a spatial understanding understand anything? Wiil it do so with parts, seen as magnitudes or as points? If it is points, the understanding will never get through them all. If magnitudes, it will understand things an unlimited number of times. | |
From: Aristotle (De Anima [c.329 BCE], 407a09) | |
A reaction: This seems to be a strong commitment to the idea that the mind is not physical because it is necessarily non-spatial. |
1717 | If the soul is composed of many physical parts, it can't be a true unity [Aristotle] |
Full Idea: If the soul is composed of parts of the body, or the harmony of the elements composing the body, there will be many souls, and everywhere in the body. | |
From: Aristotle (De Anima [c.329 BCE], 408a15) | |
A reaction: We will ignore "everywhere in the body", but the rest seems to me exactly right. The idea of the unity of the soul is an understandable and convenient assumption, but it leads to all sorts of confusion. A crowd remains unified if half its members leave. |
24053 | If a soul have parts, what unites them? [Aristotle] |
Full Idea: What is it that holds the soul together, if it by nature has parts? For surely it cannot be the body. For it seems on the contrary that it is rather the soul that holds the body together? | |
From: Aristotle (De Anima [c.329 BCE], 411b05) | |
A reaction: This is the hylomorphic view of a human, that the soul is the form that give unity to the matter. To do the job, presumably the form or soul need an intrinsic unity of its own, and hence cannot have parts. Apart from the need for unifying glue. |
1721 | What unifies the soul would have to be a super-soul, which seems absurd [Aristotle] |
Full Idea: If soul has parts, what holds them together? Not body, because that is united by soul. If a thing unifies the soul, then THAT is the soul (unless it too has parts, which would lead to an infinite regress). Best to say the soul is a unity. | |
From: Aristotle (De Anima [c.329 BCE], 411b10) | |
A reaction: You don't need a 'thing' to unify something (like a crowd). I say the body holds the soul together, not physically, but because the body's value permeates thought. The body is the focused interest of the soul, like parents kept together by their child. |
1735 | In a way the soul is everything which exists, through its perceptions and thoughts [Aristotle] |
Full Idea: The soul is in a way all the things that exist, for all the things that exist are objects either of perception or of thought. | |
From: Aristotle (De Anima [c.329 BCE], 431b20) | |
A reaction: Sounds very like Berkeley's empirical version of idealism. It also seems to imply modern externalist (anti-individualist) understandings of the mind (which strike me as false). |
24061 | If we divide the mind up according to its capacities, there are a lot of them [Aristotle] |
Full Idea: For those who divide the soul into parts, and divide and separate them in accord with their capacities, the parts turn out to be very many. | |
From: Aristotle (De Anima [c.329 BCE], 433a32) | |
A reaction: I accept the warning. The capacities which interest me are those which seem to generate our basic ontology, but if the capacities become fine-grained, they are legion. |
24062 | Self-moving animals must have desires, and that entails having imagination [Aristotle] |
Full Idea: If an animal has a desiring part, it is capable of moving itself. A desiring part, however, cannot exist without an imagination, and all imagination is either rationally calculative or perceptual. Hence in the latter the other animals also have a share. | |
From: Aristotle (De Anima [c.329 BCE], 433b27) | |
A reaction: Maybe if you asked people whether other animals are imaginative they would say no, but this argument is strong support for the positive view. |
1710 | Emotion involves the body, thinking uses the mind, imagination hovers between them [Aristotle] |
Full Idea: Most affections (like anger) seem to involve the body, but thinking seems distinctive of the soul. But if this requires imagination, it too involves the body. Only pure mental activity would prove the separation of the two. | |
From: Aristotle (De Anima [c.329 BCE], 403a08-) | |
A reaction: What an observant man! Modern neuroscience is bringing out the fact that emotion is central to all mental life. We can't recognise faces without it. I say imagination is essential to pure reason, and that seems emotional too. Reason is physical. |
24056 | The soul (or parts of it) is not separable from the body [Aristotle] |
Full Idea: That the soul is not separable from the body - or that certain parts of it are not, if it naturally has parts - is quite clear. | |
From: Aristotle (De Anima [c.329 BCE], 413a04) | |
A reaction: This doesn't make him a physicalist. I've seen him described in modern terms as a functionalist, but that makes the mind abstract and the body concrete. Perhaps he is an 'Integrationist' (as Descartes might be in his 'pilot' passage). |
24039 | All the emotions seem to involve the body, simultaneously with the feeling [Aristotle] |
Full Idea: The affections of the soul - spiritedness, fear, pity, confidence, joy, loving, hating - would all seem to involve the body, since at the same time as these the body is affected in a certain way. | |
From: Aristotle (De Anima [c.329 BCE], 403a16) | |
A reaction: Aristotle was not a physicalist, but this resembles the pilot-in-the-ship passage in Descartes, accepting the very close links. |
24050 | If soul is separate from body, why does it die when the body dies? [Aristotle] |
Full Idea: If the soul is something distinct from the mixture, why then are the being for flesh and for the other parts of the animal destroyed at the same time? | |
From: Aristotle (De Anima [c.329 BCE], 408a25) | |
A reaction: An obvious response to this reasonable question is to say that we see the body die, but not the soul, so the soul doesn't die. The problem is then to find some evidence for the soul's continued existence. |
24049 | Thinkers place the soul within the body, but never explain how they are attached [Aristotle] |
Full Idea: There is another absurdity which follows, …since they attach the soul to a body, and place it in the body, without further determining the cause due to which this attachment comes about. …Yet this seems necessary, because this association produces action. | |
From: Aristotle (De Anima [c.329 BCE], 407b14) | |
A reaction: A clear statement of the interaction objection to full substance dualism. Critics say that dualists have to invoke a 'miracle' at this point. |
1514 | Early thinkers concentrate on the soul but ignore the body, as if it didn't matter what body received the soul [Aristotle] |
Full Idea: Early thinkers try only to describe the soul, but they fail to go into any kind of detail about the body which is to receive the soul, as if it were possible (as it is in the Pythagorean tales) for just any old soul to be clothed in just any old body. | |
From: Aristotle (De Anima [c.329 BCE], 407b20) | |
A reaction: Precisely. Anyone who seriously believes that a human mind can be reincarnated in a flea needs their mind examined. Actually they need their brain examined, but that probably wouldn't impress them. I can, of course, imagine moving into a flea. |
2683 | Aristotle has a problem fitting his separate reason into the soul, which is said to be the form of the body [Ackrill on Aristotle] |
Full Idea: In 'De Anima' Aristotle cannot fit his account of separable reason - which is not the form of a body - into his general theory that the soul is the form of the body. | |
From: comment on Aristotle (De Anima [c.329 BCE]) by J.L. Ackrill - Aristotle on Eudaimonia p.33 | |
A reaction: A penetrating observation. Possibly the biggest challenge for a modern physicalist is to give a reductive account of 'pure' reason, in terms of brain events or brain functions. |
1718 | Does the mind think or pity, or does the whole man do these things? [Aristotle] |
Full Idea: Perhaps it would be better not to say that the soul pities or learns or thinks, but that the man does in virtue of the soul. | |
From: Aristotle (De Anima [c.329 BCE], 408b12) | |
A reaction: This can be seen as incipient behaviourism in Aristotle's view. It echoes the functionalist view that what matters is not what the mind is, or is made of, but what it does. |
13275 | The soul and the body are inseparable, like the imprint in some wax [Aristotle] |
Full Idea: We should not enquire whether the soul and the body are one thing, any more than whether the wax and its imprint are, or in general whether the matter of each thing is one with that of which it is the matter. | |
From: Aristotle (De Anima [c.329 BCE], 412b06) | |
A reaction: This is his hylomorphist view of objects, so that the soul is the 'form' which bestows identity (and power) on the matter of which it is made. This remark is thoroughly physicalist. |
1733 | Thinking is not perceiving, but takes the form of imagination and speculation [Aristotle] |
Full Idea: Thinking, then, is something other than perceiving, and its two kinds are held to be imagination and supposition. | |
From: Aristotle (De Anima [c.329 BCE], 427b28) |
23307 | Aristotle makes belief a part of reason, but sees desires as separate [Aristotle, by Sorabji] |
Full Idea: Aristotle insists [against Plato] that desires, even rational desires, are a capacity distinct from reason, as is perception. Belief is included within reason. And he sometimes distinguishes steps of reasoning from insight. | |
From: report of Aristotle (De Anima [c.329 BCE], 428-432) by Richard Sorabji - Rationality 'Shifting' | |
A reaction: So the standard picture of desire as permanently in conflict with reason comes from Aristotle. Maybe Plato is right on that one (though he doesn't say much about it). Since objectivity needs knowledge, reason does need belief. |
16383 | Puzzled Pierre has two mental files about the same object [Recanati on Kripke] |
Full Idea: In Kripke's puzzle about belief, the subject has two distinct mental files about one and the same object. | |
From: comment on Saul A. Kripke (A Puzzle about Belief [1979]) by François Recanati - Mental Files 17.1 | |
A reaction: [Pierre distinguishes 'London' from 'Londres'] The Kripkean puzzle is presented as very deep, but I have always felt there was a simple explanation, and I suspect that this is it (though I will leave the reader to think it through, as I'm very busy…). |
24060 | Self-controlled follow understanding, when it is opposed to desires [Aristotle] |
Full Idea: Self-controlled people, even when they desire and have an appetite for things, do not do these things for which they have the desire, but instead follow the understanding. | |
From: Aristotle (De Anima [c.329 BCE], 433a06) | |
A reaction: If modern discussions would stop talking of 'weakness of will', and talk instead of 'control' and its lack, the whole issue would become clearer. Akrasia is then seen, for example, as an action of the whole person, not of some defective part. |
4376 | Pleasure and pain are perceptions of things as good or bad [Aristotle] |
Full Idea: To experience pleasure or pain is to be active with the perceptive mean in relation to good or bad as such. | |
From: Aristotle (De Anima [c.329 BCE], 431a10) | |
A reaction: A bizarre view which is interesting, but strikes me as wrong. We are drawn towards pleasure, but judgement can pull us away again, and 'good' is in the judgement, not in the feeling. |
16956 | To explain generosity in a person, you must understand a generous action [Dummett] |
Full Idea: It cannot be explained what it is for a person to be generous without first explaining what it is for an action to be generous. | |
From: Michael Dummett (Could There Be Unicorns? [1983], 4) | |
A reaction: I presume a slot machine can't be 'generous', even if it favours the punter, so you can't specify a generous action without making reference to the person. A benign circle, as Aristotle says. |
1740 | Nature does nothing in vain [Aristotle] |
Full Idea: Nature does nothing in vain. | |
From: Aristotle (De Anima [c.329 BCE], 434a31) |
16954 | Generalised talk of 'natural kinds' is unfortunate, as they vary too much [Dummett] |
Full Idea: In my view, Kripke's promotion of 'natural kinds', coverning chemical substances and animal and plant species, is unfortunate, since these are rather different types of things, and words used for them behave differently. | |
From: Michael Dummett (Could There Be Unicorns? [1983], 2) | |
A reaction: My view is that the only significant difference among natural kinds is their degree of stability in character. Presumably particles, elements and particular molecules are fairly invariant, but living things evolve. |
24045 | Movement is spatial, alteration, withering or growth [Aristotle] |
Full Idea: There a four sorts of movement - spatial movement, alteration, withering and growth. | |
From: Aristotle (De Anima [c.329 BCE], 406a12) | |
A reaction: Large parts of Aristotle's writings attempt to explain these four. |
1738 | Practical reason is based on desire, so desire must be the ultimate producer of movement [Aristotle] |
Full Idea: There seem to be two producers of movement, either desire or practical intellect, but practical reason begins in desire. | |
From: Aristotle (De Anima [c.329 BCE], 433a16) |
24044 | Movement can be intrinsic (like a ship) or relative (like its sailors) [Aristotle] |
Full Idea: It is not necessary for what moves things to be itself moving. For a thing can be moving in two ways - with reference to something else, or intrinsically. A ship is moving intrinsically, but sailors move because they are in something that is moving. | |
From: Aristotle (De Anima [c.329 BCE], 406a03) | |
A reaction: I love the way that Aristotle is desperate to explain the puzzle of movement, yet we just take it for granted. Very illuminating about puzzles. Newton's First Law of Motion. |
1739 | If all movement is either pushing or pulling, there must be a still point in between where it all starts [Aristotle] |
Full Idea: Every movement being either a push or a pull, there must be a still point as with the circle, and this will be the point of departure for the movement. | |
From: Aristotle (De Anima [c.329 BCE], 433b26) |
24064 | If something is pushed, it pushes back [Aristotle] |
Full Idea: What has pushed something else makes the latter push as well. | |
From: Aristotle (De Anima [c.329 BCE], 435b30) | |
A reaction: Aristotle seems to have spotted that this is intrinsic to massive bodies, and is not just friction etc. Newton adds a vector to Aristotle's insight. |
24063 | What is born has growth, a prime, and a withering away [Aristotle] |
Full Idea: What has been born must have growth, a prime of life, and a time of withering away. | |
From: Aristotle (De Anima [c.329 BCE], 434a23) | |
A reaction: Modern biologists don't seem much interested in the 'prime of life', but for Aristotle it is crucial, as the fulfilment of a thing's essential nature. Nietzsche would probably agree with Aristotle on this. We dread seeing one period of life as 'superior'. |