18 ideas
| 192 | Only one thing can be contrary to something [Plato] |
| Full Idea: To everything that admits of a contrary there is one contrary and no more. | |
| From: Plato (Protagoras [c.380 BCE], 332c) | |
| A reaction: The sort of thing for which a modern philosopher would demand a proof (and then reject when the proof couldn't be found), where a Greek is happy to assert it as self-evident. I can't think of a counterexample. |
| 190 | If asked whether justice itself is just or unjust, you would have to say that it is just [Plato] |
| Full Idea: If someone asked me 'Is justice itself just or unjust?' I should answer that it was just, wouldn't you? I agree. | |
| From: Plato (Protagoras [c.380 BCE], 330c) |
| 16627 | If you remove the accidents from a horse and a lion, the intellect can't tell them apart [Francis of Marchia] |
| Full Idea: Let all accidents be removed from a lion and a horse. Nothing remains in the intellect to distinguish them. We distinguish a lion and a horse only by analogy to the accidents proper to each. The intellect does not have an essential concept of either one. | |
| From: Francis of Marchia (Commentary on Sentences [1330], I.3.1), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 07.3 | |
| A reaction: What a very nice thought experiment, and very convincing about how the mind perceives such things. But we don't believe horse and lion just consists of the surface properties of them which we experience. |
| 20184 | The only real evil is loss of knowledge [Plato] |
| Full Idea: The only real kind of faring ill is the loss of knowledge. | |
| From: Plato (Protagoras [c.380 BCE], 345b) | |
| A reaction: This must crucially involve the intellectualist view (of Socrates) that virtuos behaviour results from knowledge, and moral wickedness is the result of ignorance. It is hard to see how forgetting a phone number is evil. |
| 20185 | The most important things in life are wisdom and knowledge [Plato] |
| Full Idea: It would be shameful indeed to say that wisdom and knowledge are anything but the most powerful forces in human activity. | |
| From: Plato (Protagoras [c.380 BCE], 352d) | |
| A reaction: He lumps wisdom and knowledge together, and I think we can take 'knowledge' to mean something like understanding, because obviously mere atomistic propositional knowledge can be utterly trivial. |
| 23633 | Many truths seem obvious, and point to universal agreement - which is what we find [Reid] |
| Full Idea: There are many truths so obvious to the human faculties, that it should be expected that men should universally agree in them. And this is actually found to be the case with regard to many truths, against which we find no dissent. | |
| From: Thomas Reid (Essays on Intellectual Powers 1: Preliminary [1785], 2) | |
| A reaction: He says that a few sceptical philosophers may disagree. This is a nice statement of his creed of common sense. I agree with him, and Aristotle observes the same fact. |
| 191 | Everything resembles everything else up to a point [Plato] |
| Full Idea: Everything resembles everything else up to a point. | |
| From: Plato (Protagoras [c.380 BCE], 331d) |
| 23630 | Only philosophers treat ideas as objects [Reid] |
| Full Idea: The vulgar allow that an 'idea' implies a mind that thinks, an act of mind which we call thinking, and an object about which we think. But the philosopher conceives a fourth - the idea, which is the immediate object. …I believe this to be a mere fiction. | |
| From: Thomas Reid (Essays on Intellectual Powers 1: Preliminary [1785], 1) | |
| A reaction: Another example, to add to Yablo's list, of abstract objects invented by philosophers to fill holes in their theories. This one is illuminating, because we all say 'I've got an idea'. Cf discussions of the redundancy of truth. Cf propositions. |
| 23629 | The ambiguity of words impedes the advancement of knowledge [Reid] |
| Full Idea: There is no greater impediment to the advancement of knowledge than the ambiguity of words. | |
| From: Thomas Reid (Essays on Intellectual Powers 1: Preliminary [1785], 1) | |
| A reaction: He means that ambiguity leads to long pointless disagreements. |
| 203 | Courage is knowing what should or shouldn't be feared [Plato] |
| Full Idea: Knowledge of what is and is not to be feared is courage. | |
| From: Plato (Protagoras [c.380 BCE], 360d) |
| 202 | No one willingly and knowingly embraces evil [Plato] |
| Full Idea: No one willingly goes to meet evil, or what he thinks is evil. | |
| From: Plato (Protagoras [c.380 BCE], 358d) | |
| A reaction: Presumably people who actively choose satanism can override this deep-seated attitude. But their adherence to evil usually seems to be rather restrained. A danger of tautology with ideas like this. |
| 193 | Some things are good even though they are not beneficial to men [Plato] |
| Full Idea: 'Do you mean by good those things that are beneficial to men?' 'Not only those. I call some things which are not beneficial good as well'. | |
| From: Plato (Protagoras [c.380 BCE], 333e) | |
| A reaction: Examples needed, but this would be bad news for utilitarians. Good health is not seen as beneficial if it is taken for granted. Not being deaf. |
| 197 | Some pleasures are not good, and some pains are not evil [Plato] |
| Full Idea: There are some pleasures which are not good, and some pains which are not evil. | |
| From: Plato (Protagoras [c.380 BCE], 351d) | |
| A reaction: Sadism and child birth. Though Bentham (I think) says that there is nothing good about the pain, since the event would obviously be better without it. |
| 200 | People tend only to disapprove of pleasure if it leads to pain, or prevents future pleasure [Plato] |
| Full Idea: The only reason the common man disapproves of pleasures is if they lead to pain and deprive us of future pleasures. | |
| From: Plato (Protagoras [c.380 BCE], 354a) | |
| A reaction: Plato has a strong sense that some pleasures are just innately depraved and wicked. If those pleasure don't hurt anyone, it is very hard to pinpoint what is wrong with them. |
| 189 | If we punish wrong-doers, it shows that we believe virtue can be taught [Plato] |
| Full Idea: Athenians inflict punishment on wrong-doers, which shows that they too think it possible to impart and teach goodness. | |
| From: Plato (Protagoras [c.380 BCE], 324c) |
| 188 | Socrates did not believe that virtue could be taught [Plato] |
| Full Idea: Socrates: I do not believe that virtue can be taught. | |
| From: Plato (Protagoras [c.380 BCE], 320b) |
| 204 | Socrates is contradicting himself in claiming virtue can't be taught, but that it is knowledge [Plato] |
| Full Idea: Socrates is contradicting himself by saying virtue is not teachable, and yet trying to demonstrate that every virtue is knowledge. | |
| From: Plato (Protagoras [c.380 BCE], 361b) |
| 23632 | Similar effects come from similar causes, and causes are only what are sufficient for the effects [Reid] |
| Full Idea: A first principle is that similar effects proceed from the same or similar causes; that we ought to admit of no other causes …but such as are sufficient to account for the effects. | |
| From: Thomas Reid (Essays on Intellectual Powers 1: Preliminary [1785], 2) | |
| A reaction: He treats these as a priori axioms of natural philosophy. In evolution similar causes seem to produce startlingly divergent effects, such as the mating needs of male birds. |