34 ideas
| 326 | For relaxation one can consider the world of change, instead of eternal things [Plato] |
| Full Idea: If, for relaxation, one gives up discussing eternal things, it is pleasant to consider likely accounts of the world of change. | |
| From: Plato (Timaeus [c.349 BCE], 59c) | |
| A reaction: To understand this, examine Plato's example of the Line at 'Republic' 509d. |
| 315 | Philosophy is the supreme gift of the gods to mortals [Plato] |
| Full Idea: Philosophy is the greatest gift the gods have ever given or ever will give to mortals. | |
| From: Plato (Timaeus [c.349 BCE], 47b) | |
| A reaction: I wonder why they gave it to us? |
| 306 | Nothing can come to be without a cause [Plato] |
| Full Idea: Nothing can come to be without a cause. | |
| From: Plato (Timaeus [c.349 BCE], 28a) |
| 9837 | 0 is not a number, as it answers 'how many?' negatively [Husserl, by Dummett] |
| Full Idea: Husserl contends that 0 is not a number, on the grounds that 'nought' is a negative answer to the question 'how many?'. | |
| From: report of Edmund Husserl (Philosophy of Arithmetic [1894], p.144) by Michael Dummett - Frege philosophy of mathematics Ch.8 | |
| A reaction: I seem to be in a tiny minority in thinking that Husserl may have a good point. One apple is different from one orange, but no apples are the same as no oranges. That makes 0 a very peculiar number. See Idea 9838. |
| 9576 | Multiplicity in general is just one and one and one, etc. [Husserl] |
| Full Idea: Multiplicity in general is no more than something and something and something, etc.; ..or more briefly, one and one and one, etc. | |
| From: Edmund Husserl (Philosophy of Arithmetic [1894], p.85), quoted by Gottlob Frege - Review of Husserl's 'Phil of Arithmetic' | |
| A reaction: Frege goes on to attack this idea fairly convincingly. It seems obvious that it is hard to say that you have seventeen items, if the only numberical concept in your possession is 'one'. How would you distinguish 17 from 16? What makes the ones 'multiple'? |
| 17444 | Husserl said counting is more basic than Frege's one-one correspondence [Husserl, by Heck] |
| Full Idea: Husserl famously argued that one should not explain number in terms of equinumerosity (or one-one correspondence), but should explain equinumerosity in terms of sameness of number, which should be characterised in terms of counting. | |
| From: report of Edmund Husserl (Philosophy of Arithmetic [1894]) by Richard G. Heck - Cardinality, Counting and Equinumerosity 3 | |
| A reaction: [Heck admits he hasn't read the Husserl] I'm very sympathetic to Husserl, though nearly all modern thinking favours Frege. Counting connects numbers to their roots in the world. Mathematicians seem oblivious of such things. |
| 324 | Before the existence of the world there must have been being, space and becoming [Plato] |
| Full Idea: There were, before the world came into existence, being, space, and becoming, three distinct realities. | |
| From: Plato (Timaeus [c.349 BCE], 52d) |
| 20364 | The apprehensions of reason remain unchanging, but reasonless sensation shows mere becoming [Plato] |
| Full Idea: That which is apprehended by intelligence and reason is always in the same state, but that which is conceived by opinion with the help of sensation and without reason is always in a process of becoming and perishing, and never really is. | |
| From: Plato (Timaeus [c.349 BCE], 28a) | |
| A reaction: Lots of problems with this, of which I take the main one to be the idea that sensation is 'without reason', as if there were a sharp dichotomy in our ways of evaluating reality. Laws of nature seem to be laws of change, not of stasis. |
| 12042 | Plato's Forms were seen as part of physics, rather than of metaphysics [Plato, by Annas] |
| Full Idea: In the ancient world Plato's Theory of Forms was mostly seen as one aspect of Plato's 'physics' or theory of the world (rather than as 'metaphysics'). | |
| From: report of Plato (Timaeus [c.349 BCE]) by Julia Annas - Ancient Philosophy: very short introduction Ch.5 | |
| A reaction: This is how I also see the theory, but then I am inclined to see religion as a rather startling branch of speculative physics. Annas cites 'Timaeus' as the key text for this. |
| 307 | Something will always be well-made if the maker keeps in mind the eternal underlying pattern [Plato] |
| Full Idea: Whenever the maker of anything keeps his eye on the eternally unchanging and uses it as his pattern for the form and function of his product the result must be good. | |
| From: Plato (Timaeus [c.349 BCE], 28b) |
| 318 | In addition to the underlying unchanging model and a changing copy of it, there must also be a foundation of all change [Plato] |
| Full Idea: In addition to an eternal unchanging model and a visible and changing copy of reality, there must be a third part, the receptacle and nurse of all becoming and change. | |
| From: Plato (Timaeus [c.349 BCE], 49b) | |
| A reaction: cf Aristotle's criticism in Metaphysics |
| 321 | For knowledge and true opinion to be different there must be Forms; otherwise we are just stuck with sensations [Plato] |
| Full Idea: If intelligence and true opinion are different, then the forms must exist, but if they are the same, then what our senses perceive must be the most certain reality. | |
| From: Plato (Timaeus [c.349 BCE], 51d) |
| 317 | The universe is basically an intelligible and unchanging model, and a visible and changing copy of it [Plato] |
| Full Idea: Our basic description of the universe contained an intelligible and unchanging model, and a visible and changing copy of it. | |
| From: Plato (Timaeus [c.349 BCE], 48e) |
| 334 | Only bird-brained people think astronomy is entirely a matter of evidence [Plato] |
| Full Idea: Birds are empty-headed men who grew feathers instead of hair, because they were interested in astronomy but thought it was entirely a matter of physical evidence. | |
| From: Plato (Timaeus [c.349 BCE], 91d) |
| 5962 | Plato says the soul is ordered by number [Plato, by Plutarch] |
| Full Idea: Plato regards the substance of soul not as number but as being ordered by number. | |
| From: report of Plato (Timaeus [c.349 BCE]) by Plutarch - 68: Generation of the soul in 'Timaeus' 1023 | |
| A reaction: This remark points towards Plato's esoteric doctrines, which are some sort of mathematical metaphysics. The idea that order and numbers are in some way connected is one of the most powerful in western civilization, with undeniable appeal. |
| 9575 | Husserl identifies a positive mental act of unification, and a negative mental act for differences [Husserl, by Frege] |
| Full Idea: Husserl identifies a 'unitary mental act' where several contents are connected or related to one another, and also a difference-relation where two contents are related to one another by a negative judgement. | |
| From: report of Edmund Husserl (Philosophy of Arithmetic [1894], p.73-74) by Gottlob Frege - Review of Husserl's 'Phil of Arithmetic' p.322 | |
| A reaction: Frege is setting this up ready for a fairly vicious attack. Where Hume has a faculty for spotting resemblances, it is not implausible that we should also be hard-wired to spot differences. 'You look different; have you changed your hair style?' |
| 330 | No one wants to be bad, but bad men result from physical and educational failures, which they do not want or choose [Plato] |
| Full Idea: No one wishes to be bad, but a bad man is bad because of some flaw in his physical makeup and failure in his education, neither of which he likes or chooses. | |
| From: Plato (Timaeus [c.349 BCE], 86e) |
| 21214 | We clarify concepts (e.g. numbers) by determining their psychological origin [Husserl, by Velarde-Mayol] |
| Full Idea: Husserl said that the clarification of any concept is made by determining its psychological origin. He is concerned with the psychological origins of the operation of calculating cardinal numbers. | |
| From: report of Edmund Husserl (Philosophy of Arithmetic [1894]) by Victor Velarde-Mayol - On Husserl 2.2 | |
| A reaction: This may not be the same as the 'psychologism' that Frege so despised, because Husserl is offering a clarification, rather than the intrinsic nature of number concepts. It is not a theory of the origin of numbers. |
| 9819 | Psychologism blunders in focusing on concept-formation instead of delineating the concepts [Dummett on Husserl] |
| Full Idea: Husserl substitutes his account of the process of concept-formation for a delineation of the concept. It is above all in making this substitution that psychologism is objectionable (and Frege opposed it so vehemently). | |
| From: comment on Edmund Husserl (Philosophy of Arithmetic [1894]) by Michael Dummett - Frege philosophy of mathematics Ch.2 | |
| A reaction: While this is a powerful point which is a modern orthodoxy, it hardly excludes a study of concept-formation from being of great interest for other reasons. It may not appeal to logicians, but it is crucial part of the metaphysics of nature. |
| 9851 | Husserl wanted to keep a shadowy remnant of abstracted objects, to correlate them [Dummett on Husserl] |
| Full Idea: Husserl saw that abstracted units, though featureless, must in some way retain their distinctness, some shadowy remnant of their objects. So he wanted to correlate like-numbered sets, not just register their identity, but then abstractionism fails. | |
| From: comment on Edmund Husserl (Philosophy of Arithmetic [1894]) by Michael Dummett - Frege philosophy of mathematics Ch.12 | |
| A reaction: Abstractionism is held to be between the devil and the deep blue sea, of depending on units which are identifiable, when they are defined as devoid of all individuality. We seem forced to say that the only distinction between them is countability. |
| 316 | Music has harmony like the soul, and serves to reorder disharmony within us [Plato] |
| Full Idea: Music has harmonic motions like the orbits of the soul, and is not for irrational pleasure, but to reduce to order any disharmony in the revolutions within us. | |
| From: Plato (Timaeus [c.349 BCE], 47d) |
| 1590 | The just man does not harm his enemies, but benefits everyone [Plato] |
| Full Idea: First, Socrates, you told me justice is harming your enemies and helping your friends. But later it seemed that the just man, since everything he does is for someone's benefit, never harms anyone. | |
| From: Plato (Clitophon [c.372 BCE], 410b) | |
| A reaction: Socrates certainly didn't subscribe to the first view, which is the traditional consensus in Greek culture. In general Socrates agreed with the views later promoted by Jesus. |
| 332 | One should exercise both the mind and the body, to avoid imbalance [Plato] |
| Full Idea: One should preserve a balance and avoid exercising the mind or body without the other; mathematicians should exercise physically, and athletes mentally. | |
| From: Plato (Timaeus [c.349 BCE], 88c) | |
| A reaction: Excellent, and very modern. Use it or lose it. It suggests that Plato had a fairly holistic view of a human being, and saw mind and body as closely integrated. |
| 328 | Everything that takes place naturally is pleasant [Plato] |
| Full Idea: Everything that takes place naturally is pleasant. | |
| From: Plato (Timaeus [c.349 BCE], 81e) | |
| A reaction: Not many people would agree with this. I recently watched a sparrowhawk eat a pigeon in my garden. This is the source of the stoic formula of living according to nature. |
| 322 | Intelligence is the result of rational teaching; true opinion can result from irrational persuasion [Plato] |
| Full Idea: Intelligence is produced by teaching, involves truth and reason, and cannot be moved; true opinion involves persuasion, is irrational and can be moved. | |
| From: Plato (Timaeus [c.349 BCE], 51e) |
| 331 | Bad governments prevent discussion, and discourage the study of virtue [Plato] |
| Full Idea: Under a bad government discussion, both public and private, is bad, and no courses of study are available to cure faults of character. | |
| From: Plato (Timaeus [c.349 BCE], 87b) |
| 310 | The creator of the cosmos had no envy, and so wanted things to be as like himself as possible [Plato] |
| Full Idea: This changing cosmos was made because its maker is good, and therefore lacks envy; he therefore wished all things to be as like himself as possible. | |
| From: Plato (Timaeus [c.349 BCE], 29e) |
| 311 | The cosmos must be unique, because it resembles the creator, who is unique [Plato] |
| Full Idea: So that our universe can resemble the perfect living creature in being unique, the universe was, is and will continue to be its maker's only creation. | |
| From: Plato (Timaeus [c.349 BCE], 31c) |
| 325 | We must consider the four basic shapes as too small to see, only becoming visible in large numbers [Plato] |
| Full Idea: We must think of the individual units of all four basic shapes as being far too small to be visible, and only becoming visible when massed together in large numbers. | |
| From: Plato (Timaeus [c.349 BCE], 56c) |
| 327 | There are two types of cause, the necessary and the divine [Plato] |
| Full Idea: We must distinguish two types of cause, the necessary and the divine. | |
| From: Plato (Timaeus [c.349 BCE], 68e) |
| 314 | Heavenly movements gave us the idea of time, and caused us to inquire about the heavens [Plato] |
| Full Idea: Days, months, years and solstices have caused the invention of number, given us the notion of time, and caused us to inquire into the nature of the universe. | |
| From: Plato (Timaeus [c.349 BCE], 47a) |
| 312 | Time came into existence with the heavens, so that there will be a time when they can be dissolved [Plato] |
| Full Idea: Time came into being with the heavens, so that they should be dissolved together if ever they are dissolved. | |
| From: Plato (Timaeus [c.349 BCE], 38c) |
| 309 | Clearly the world is good, so its maker must have been concerned with the eternal, not with change [Plato] |
| Full Idea: If the world is beautiful and its maker good, he had an eye on the eternal; if not, on that which is subject to change; clearly the world is the fairest of things, and he the best of causes, so it is eternal. | |
| From: Plato (Timaeus [c.349 BCE], 29a) |
| 308 | If the cosmos is an object of perception then it must be continually changing [Plato] |
| Full Idea: The cosmos is visible, tangible and corporeal, and therefore perceptible by the senses; therefore it is an object of opinion and sensation, and therefore change and coming into being. | |
| From: Plato (Timaeus [c.349 BCE], 28d) |