51 ideas
| 162 | Can we understand an individual soul without knowing the soul in general? [Plato] |
| Full Idea: Do you think it possible to form an adequate conception of the nature of an individual soul without considering the nature of soul in general? | |
| From: Plato (Phaedrus [c.366 BCE], 270c) | |
| A reaction: Do animals understand anything (as opposed to simply being aware of things)? |
| 160 | The highest ability in man is the ability to discuss unity and plurality in the nature of things [Plato] |
| Full Idea: When I believe that I have found in anyone the ability to discuss unity and plurality as they exist in the nature of things, I follow his footsteps as if he was a god. | |
| From: Plato (Phaedrus [c.366 BCE], 266b) | |
| A reaction: This sounds like the problem of identity, which is at the heart of modern metaphysics. |
| 21360 | Unobservant thinkers tend to dogmatise using insufficient facts [Aristotle] |
| Full Idea: Those whom devotion to abstract discussions has rendered unobservant of the facts are too ready to dogmatise on the basis of a few observations. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 316a09) | |
| A reaction: I totally approve of the idea that a good philosopher should be 'observant'. Prestige in modern analytic philosophy comes from logical ability. There should be some rival criterion for attentiveness to facts, with equal prestige. |
| 166 | A speaker should be able to divide a subject, right down to the limits of divisibility [Plato] |
| Full Idea: A speaker must be able to define a subject generically, and then to divide it into its various specific kinds until he reaches the limits of divisibility. | |
| From: Plato (Phaedrus [c.366 BCE], 277b) |
| 13212 | Infinity is only potential, never actual [Aristotle] |
| Full Idea: Nothing is actually infinite. A thing is infinite only potentially. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 318a21) | |
| A reaction: Aristotle is the famous spokesman for this view, though it reappeared somewhat in early twentieth century discussions (e.g. Hilbert). I sympathise with this unfashionable view. Multiple infinites are good fun, but no one knows what they really are. |
| 13221 | Existence is either potential or actual [Aristotle] |
| Full Idea: Some things are-potentially while others are-actually. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 327b24) | |
| A reaction: I've read a lot of Aristotle, but am still not quite clear what this distinction means. I like the distinction between a thing's actual being and its 'modal profile', but the latter may extend well beyond what Aristotle means by potential being. |
| 16100 | True change is in a thing's logos or its matter, not in its qualities [Aristotle] |
| Full Idea: In that which underlies a change there is a factor corresponding to the definition [logon] and there is a material factor. When a change is in these constitutive factors there is coming to be or passing away, but in a thing's qualities it is alteration. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 317a24) | |
| A reaction: This seems to be a key summary of Aristotle's account of change, in the context of his hylomorphism (form-plus-matter). The logos is the account of the thing, which seems to be the definition, which seems to give the form (principle or structure). |
| 16101 | A change in qualities is mere alteration, not true change [Aristotle] |
| Full Idea: When a change occurs in the qualities [pathesi] and is accidental [sumbebekos], there is alteration (rather than true change). | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 317a27) | |
| A reaction: [tr. partly Gill] Aristotle doesn't seem to have a notion of 'properties' in quite our sense. 'Pathe' seems to mean experienced qualities, rather than genuine causal powers. Gill says 'pathe' are always accidental. |
| 12133 | If the substratum persists, it is 'alteration'; if it doesn't, it is 'coming-to-be' or 'passing-away' [Aristotle] |
| Full Idea: Since we must distinguish the substratum and the property whose nature is to be predicated of the substratum,..there is alteration when the substratum persists...but when nothing perceptible persists as a substratum, this is coming-to-be and passing-away. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 319b08-16) | |
| A reaction: As usual, Aristotle clarifies the basis of the problem, by distinguishing two different types of change. Notice the empirical character of his approach, resting on whether or not the substratum is 'perceptible'. |
| 13213 | All comings-to-be are passings-away, and vice versa [Aristotle] |
| Full Idea: Every coming-to-be is a passing away of something else and every passing-away some other thing's coming-to-be. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 319a07) | |
| A reaction: This seems to be the closest that Aristotle gets to sympathy with the Heraclitus view that all is flux. When a sparrow dies and disappears, I am not at all clear what comes to be, except some ex-sparrow material. |
| 7953 | Reasoning needs to cut nature accurately at the joints [Plato] |
| Full Idea: In our reasoning we need a clear view of the ability to divide a genus into species, observing the natural joints, not mangling any of the parts, like an unskilful butcher. | |
| From: Plato (Phaedrus [c.366 BCE], 265d) | |
| A reaction: In modern times this Platonic idea has become the standard metaphor for realism. I endorse it. I think nature has joints, and we should hunt for them. There are natural sets. The joints may exist in abstract concepts, as well as in objects. |
| 16121 | I revere anyone who can discern a single thing that encompasses many things [Plato] |
| Full Idea: If I believe that someone is capable of discerning a single thing that is also by nature capable of encompassing many, I follow 'straight behind, in his footsteps, as if he were a god'. | |
| From: Plato (Phaedrus [c.366 BCE], 266b) | |
| A reaction: [Plato quote Odyssey 2.406] This is the sort of simple but profound general observation which only the early philosophers bothered to make, and no one comments on now. Encompassing many under one is the very essence of thinking. |
| 153 | It takes a person to understand, by using universals, and by using reason to create a unity out of sense-impressions [Plato] |
| Full Idea: It takes a man to understand by the use of universals, and to collect out of the multiplicity of sense-impressions a unity arrived at by a process of reason. | |
| From: Plato (Phaedrus [c.366 BCE], 249b) |
| 154 | We would have an overpowering love of knowledge if we had a pure idea of it - as with the other Forms [Plato] |
| Full Idea: What overpowering love knowledge would inspire if it could bring a clear image of itself before our sight, and the same may be said of the other forms. | |
| From: Plato (Phaedrus [c.366 BCE], 250d) | |
| A reaction: the motivation in Plato's theory |
| 12134 | Matter is the substratum, which supports both coming-to-be and alteration [Aristotle] |
| Full Idea: Matter, in the proper sense of the term, is to be identified with the substratum which is receptive of coming-to-be and passing-away; but the substratum of the remaining kinds of change is also matter, because these substrata receive contraries. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 320a03) | |
| A reaction: This must be compared with his complex discussion of the role of matter in his Metaphysics, where he has introduced 'form' as the essence of things. I don't think the two texts are inconsistent, but it's tricky... See Idea 12133 on types of change. |
| 16572 | Does the pure 'this' come to be, or the 'this-such', or 'so-great', or 'somewhere'? [Aristotle] |
| Full Idea: The question might be raised whether substance (i.e. the 'this') comes-to-be at all. Is it not rather the 'such', the 'so-great', or the 'somewhere', which comes-to-be? | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 317b21) | |
| A reaction: This is interesting because it pulls the 'tode ti', the 'this-such', apart, showing that he does have a concept of a pure 'this', which seems to constitute the basis of being ('ousia'). We can say 'this thing', or 'one of these things'. |
| 16573 | Philosophers have worried about coming-to-be from nothing pre-existing [Aristotle] |
| Full Idea: In addition, coming-to-be may proceed out of nothing pre-existing - a thesis which, more than any other, preoccupied and alarmed the earliest philosophers. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 317b29) | |
| A reaction: This is the origin of the worry about 'ex nihilo' coming-to-be. Christians tended to say that only God could create in this way. |
| 13214 | The substratum changing to a contrary is the material cause of coming-to-be [Aristotle] |
| Full Idea: The substratum [hupokeimenon?] is the material cause of the continuous occurrence of coming-to-be, because it is such as to change from contrary to contrary. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 319a19) | |
| A reaction: Presumably Aristotle will also be seeking the 'formal' cause as well as the 'material' cause (not to mention the 'efficient' and 'final' causes). |
| 13215 | If a perceptible substratum persists, it is 'alteration'; coming-to-be is a complete change [Aristotle] |
| Full Idea: There is 'alteration' when the substratum is perceptible and persists, but changes in its own properties. ...But when nothing perceptible persists in its identity as a substratum, and the thing changes as a whole, it is coming-to-be of a substance. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 319b11-17) | |
| A reaction: [compressed] Note that a substratum can be perceptible - it isn't just some hidden mystical I-know-not-what (as Locke calls it). This whole text is a wonderful source on the subject of physical change. Note too the reliance on what is perceptible. |
| 16717 | Which of the contrary features of a body are basic to it? [Aristotle] |
| Full Idea: What sorts of contrarities, and how many of them, are to be accounted 'originative sources' of body? | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 329b04) | |
| A reaction: Pasnau says these pages of Aristotle are the source of the doctrine of primary and secondary qualities. Essentially, hot, cold, wet and dry are his four primary qualities. |
| 151 | True knowledge is of the reality behind sense experience [Plato] |
| Full Idea: True knowledge is concerned with the abode of true reality, without colour or shape, intangible but utterly real, apprehensible only to the intellect. | |
| From: Plato (Phaedrus [c.366 BCE], 247c) |
| 165 | If the apparent facts strongly conflict with probability, it is in everyone's interests to suppress the facts [Plato] |
| Full Idea: There are some occasions when both prosecution and defence should positively suppress the facts in favour of probability, if the facts are improbable. | |
| From: Plato (Phaedrus [c.366 BCE], 272e) |
| 9296 | The soul is self-motion [Plato] |
| Full Idea: Self-motion is of the very nature of the soul. | |
| From: Plato (Phaedrus [c.366 BCE], 245e) | |
| A reaction: This culminates a length discussion of the soul. He gives an implausible argument that the soul is immortal, because it could never cease its self-motion. Why are we so unimpressed by motion, when the Greeks were amazed by it? |
| 23997 | Plato saw emotions and appetites as wild horses, in need of taming [Plato, by Goldie] |
| Full Idea: Plato had a conception of the emotions and our bodily appetites as being like wild horses, to be harnassed and controlled by reason. | |
| From: report of Plato (Phaedrus [c.366 BCE]) by Peter Goldie - The Emotions 4 'Education' | |
| A reaction: This seems to make Plato the patriarch of puritanism. See Symposium, as well as Phaedrus. But bringing up children can often seem like taming wild beasts. |
| 158 | An excellent speech seems to imply a knowledge of the truth in the mind of the speaker [Plato] |
| Full Idea: If a speech is to be classed as excellent, does that not presuppose knowledge of the truth about the subject of the speech in the mind of the speaker. | |
| From: Plato (Phaedrus [c.366 BCE], 259e) | |
| A reaction: I like the thought that Plato's main interest was rhetoric, but with the view that the only good rhetoric is truth-speaking. It would be hard to admire a speech if you disagreed with it. |
| 5946 | 'Phaedrus' pioneers the notion of philosophical rhetoric [Lawson-Tancred on Plato] |
| Full Idea: The purpose of the 'Phaedrus' is to pioneer the notion of philosophical rhetoric. | |
| From: comment on Plato (Phaedrus [c.366 BCE], Ch.10) by Hugh Lawson-Tancred - Plato's Republic and Greek Enlightenment | |
| A reaction: This is a wonderfully challenging view of what Plato was up to. One might connect it with Rorty's claim that philosophy should move away from epistemology and analysis, towards hermeneutics, which sounds to me like rhetoric. 'Phaedrus' is beautiful. |
| 159 | Only a good philosopher can be a good speaker [Plato] |
| Full Idea: Unless a man becomes an adequate philosopher he will never be an adequate speaker on any subject. | |
| From: Plato (Phaedrus [c.366 BCE], 261a) | |
| A reaction: Depends. Hitler showed little sign of clear philosophical thinking, but the addition of lights and uniforms seemed to sweep reasonably intelligent people along with him. |
| 155 | Beauty is the clearest and most lovely of the Forms [Plato] |
| Full Idea: Only beauty has the privilege of being the most clearly discerned and the most lovely of the forms. | |
| From: Plato (Phaedrus [c.366 BCE], 250e) | |
| A reaction: the motivation in Plato's theory |
| 143 | The two ruling human principles are the natural desire for pleasure, and an acquired love of virtue [Plato] |
| Full Idea: In each one of us there are two ruling and impelling principles: a desire for pleasure, which is innate, and an acquired conviction which causes us to aim at excellence. | |
| From: Plato (Phaedrus [c.366 BCE], 237d) | |
| A reaction: This division is too neat and simple. An obsession with pleasure I would take to be acquired. If you set out to do something, I think there is an innate desire to do it well. |
| 157 | Most pleasure is release from pain, and is therefore not worthwhile [Plato] |
| Full Idea: Life is not worth living for pleasures whose enjoyment entirely depends on previous sensation of pain, like almost all physical pleasures. | |
| From: Plato (Phaedrus [c.366 BCE], 258e) | |
| A reaction: Eating exotic food which is hard to obtain? (Pay someone to obtain it). Rock climbing. Training for sport. |
| 144 | Reason impels us towards excellence, which teaches us self-control [Plato] |
| Full Idea: The conviction which impels us towards excellence is rational, and the power by which it masters us we call self-control. | |
| From: Plato (Phaedrus [c.366 BCE], 237e) |
| 156 | Bad people are never really friends with one another [Plato] |
| Full Idea: It is not ordained that bad men should be friends with one another. | |
| From: Plato (Phaedrus [c.366 BCE], 255b) |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
| From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
| A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
| 13216 | Matter is the limit of points and lines, and must always have quality and form [Aristotle] |
| Full Idea: The matter is that of which points and lines are limits, and it is something that can never exist without quality and without form. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 320b16) | |
| A reaction: There seems to be a contradiction here somewhere. Matter has to be substantial enough to have a form, and yet seems to be the collective 'limit' of the points and lines. I wonder what 'limit' is translating? Sounds a bit too modern. |
| 17994 | The primary matter is the substratum for the contraries like hot and cold [Aristotle] |
| Full Idea: We must reckon as an 'orginal source' and as 'primary' the matter which underlies, though it is inseparable from the contrary qualities: for 'the hot' is not matter for 'the cold' nor 'cold' for 'hot', but the substratum is matter for them both. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 329a30) | |
| A reaction: A much discussed passage. |
| 13224 | There couldn't be just one element, which was both water and air at the same time [Aristotle] |
| Full Idea: No one supposes a single 'element' to persist, as the basis of all, in such a way that it is Water as well as Air (or any other element) at the same time. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 332a09) | |
| A reaction: Of course, we now think that oxygen is a key part of both water and of air, but Aristotle's basic argument still seems right. How could multiplicity be explained by a simply unity? The One is cool, but explains nothing. |
| 16594 | The Four Elements must change into one another, or else alteration is impossible [Aristotle] |
| Full Idea: These bodies (Fire, Water and the like) change into one another (and are not immutable as Empedocles and other thinkers assert, since 'alteration' would then have been impossible). | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 329b1) | |
| A reaction: This is why Aristotle proposes that matter [hule] underlies the four elements. Gill argues that by matter Aristotle means the elements. |
| 13223 | Fire is hot and dry; Air is hot and moist; Water is cold and moist; Earth is cold and dry [Aristotle] |
| Full Idea: The four couples of elementary qualities attach themselves to the apparently 'simple' bodies (Fire, Air, Earth, Water). Fire is hot and dry, whereas Air is hot and moist (being a sort of aqueous vapour); Water is cold and moist, and Earth is cold and dry. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 330b02) | |
| A reaction: This is the traditional framework accepted throughout the middle ages, and which had a huge influence on medicine. It all looks rather implausible now. Aristotle was a genius, but not critical enough about evidence. |
| 13210 | Wood is potentially divided through and through, so what is there in the wood besides the division? [Aristotle] |
| Full Idea: If having divided a piece of wood I put it together, it is equal to what it was and is one. This is so whatever the point at which I cut the wood. The wood is therefore divided potentially through and through. So what is in the wood besides the division? | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 316b11) | |
| A reaction: Part of a very nice discussion of the implications of the thought experiment of cutting something 'through and through'. It seems to me that the arguments are still relevant, in the age of quarks, electrons and strings. |
| 13211 | If a body is endlessly divided, is it reduced to nothing - then reassembled from nothing? [Aristotle] |
| Full Idea: Dividing a body at all points might actually occur, so the body will be both actually indivisible and potentially divided. Then nothing will remain and the body passes into what is incorporeal. So it might be reassembled out of points, or out of nothing. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 316b24) | |
| A reaction: [a bit compressed] This sounds like an argument in favour of atomism, but Aristotle was opposed to that view. He is aware of the contradictions that seem to emerge with infinite division. Graham Priest is interesting on the topic. |
| 13220 | Bodies are endlessly divisible [Aristotle] |
| Full Idea: Bodies are divisible through and through. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 326b27) | |
| A reaction: This is Aristotle's flat rejection of atomism, arrived at after several sustained discussions, in this text and elsewhere. I don't think we are in a position to say that Aristotle is wrong. |
| 13228 | There is no time without movement [Aristotle] |
| Full Idea: There can be no time without movement. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 337a24) | |
| A reaction: See Shoemaker's nice thought experiment as a challenge to this. Intuition seems to cry out that if movement stopped for a moment, that would not stop time, even though there was no way to measure its passing. |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
| From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |
| 16595 | If each thing can cease to be, why hasn't absolutely everything ceased to be long ago? [Aristotle] |
| Full Idea: If some one of the things 'which are' is constantly disappearing, why has not the whole of 'what is' been used up long ago and vanished away - assuming of course that the material of all the several comings-to-be was infinite? | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 318a17) | |
| A reaction: This thought is the basis of Aquinas's Third Way for proving the existence of God (as the force which prevents the vicissitudes of nature from sliding into oblivion). |
| 148 | If the prime origin is destroyed, it will not come into being again out of anything [Plato] |
| Full Idea: If the prime origin is destroyed, it will not come into being again out of anything. | |
| From: Plato (Phaedrus [c.366 BCE], 245d) | |
| A reaction: This is the essence of Aquinas's Third Way of proving God's existence. |
| 152 | The mind of God is fully satisfied and happy with a vision of reality and truth [Plato] |
| Full Idea: The mind of a god, sustained by pure intelligence and knowledge, is satisfied with the vision of reality, and nourished and made happy by the vision of truth. | |
| From: Plato (Phaedrus [c.366 BCE], 247d) |
| 13227 | Being is better than not-being [Aristotle] |
| Full Idea: Being is better than not-being. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 336b29) | |
| A reaction: [see also Metaphysics 1017a07 ff, says the note] This peculiar assumption is at the heart of the ontological argument. Is the existence of the plague bacterium, or of Satan, or of mass-murderers, superior? |
| 13226 | An Order controls all things [Aristotle] |
| Full Idea: There is an Order controlling all things. | |
| From: Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 336b13) | |
| A reaction: Presumably the translator provides the capital letter. How do we get from 'there is an order in all things' to 'there is an order which controls all things'? |
| 150 | We cannot conceive of God, so we have to think of Him as an immortal version of ourselves [Plato] |
| Full Idea: Because we have never seen or formed an adequate idea of a god, we picture him to ourselves as a being of the same kind as ourselves but immortal. | |
| From: Plato (Phaedrus [c.366 BCE], 246d) |
| 149 | There isn't a single reason for positing the existence of immortal beings [Plato] |
| Full Idea: There is not a single sound reason for positing the existence of such a being who is immortal | |
| From: Plato (Phaedrus [c.366 BCE], 246d) |
| 146 | Soul is always in motion, so it must be self-moving and immortal [Plato] |
| Full Idea: All soul is immortal, for what is always in motion is immortal. Only that which moves itself never ceases to be in motion. | |
| From: Plato (Phaedrus [c.366 BCE], 245c) |