45 ideas
21474 | Metaphysics studies the inexplicable ends of explanation [Schopenhauer] |
Full Idea: The plummet touches the bottom of the sea now at a greater depth, now at a less, but is bound to reach it somewhere sooner or later; the study of this inexplicable devolves upon metaphysics. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], I:1) | |
A reaction: This definition of metapysics contains the germ of despair about the subject. Does he hope that metaphysicians can explain what nobody else can? |
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. |
18755 | Validity is explained as truth in all models, because that relies on the logical terms [McGee] |
Full Idea: A model of a language assigns values to non-logical terms. If a sentence is true in every model, its truth doesn't depend on those non-logical terms. Hence the validity of an argument comes from its logical form. Thus models explain logical validity. | |
From: Vann McGee (Logical Consequence [2014], 4) | |
A reaction: [compressed] Thus you get a rigorous account of logical validity by only allowing the rigorous input of model theory. This is the modern strategy of analytic philosophy. But is 'it's red so it's coloured' logically valid? |
18751 | Natural language includes connectives like 'because' which are not truth-functional [McGee] |
Full Idea: Natural language includes connectives that are not truth-functional. In order for 'p because q' to be true, both p and q have to be true, but knowing the simpler sentences are true doesn't determine whether the larger sentence is true. | |
From: Vann McGee (Logical Consequence [2014], 2) |
18761 | Second-order variables need to range over more than collections of first-order objects [McGee] |
Full Idea: To get any advantage from moving to second-order logic, we need to assign to second-order variables a role different from merely ranging over collections made up of things the first-order variables range over. | |
From: Vann McGee (Logical Consequence [2014], 7) | |
A reaction: Thus it is exciting if they range over genuine properties, but not so exciting if you merely characterise those properties as sets of first-order objects. This idea leads into a discussion of plural quantification. |
18753 | An ontologically secure semantics for predicate calculus relies on sets [McGee] |
Full Idea: We can get a less ontologically perilous presentation of the semantics of the predicate calculus by using sets instead of concepts. | |
From: Vann McGee (Logical Consequence [2014], 4) | |
A reaction: The perilous versions rely on Fregean concepts, and notably Russell's 'concept that does not fall under itself'. The sets, of course, have to be ontologically secure, and so will involve the iterative conception, rather than naive set theory. |
18754 | Logically valid sentences are analytic truths which are just true because of their logical words [McGee] |
Full Idea: Logically valid sentences are a species of analytic sentence, being true not just in virtue of the meanings of their words, but true in virtue of the meanings of their logical words. | |
From: Vann McGee (Logical Consequence [2014], 4) | |
A reaction: A helpful link between logical truths and analytic truths, which had not struck me before. |
18757 | Soundness theorems are uninformative, because they rely on soundness in their proofs [McGee] |
Full Idea: Soundness theorems are seldom very informative, since typically we use informally, in proving the theorem, the very same rules whose soundness we are attempting to establish. | |
From: Vann McGee (Logical Consequence [2014], 5) | |
A reaction: [He cites Quine 1935] |
18760 | The culmination of Euclidean geometry was axioms that made all models isomorphic [McGee] |
Full Idea: One of the culminating achievements of Euclidean geometry was categorical axiomatisations, that describe the geometric structure so completely that any two models of the axioms are isomorphic. The axioms are second-order. | |
From: Vann McGee (Logical Consequence [2014], 7) | |
A reaction: [He cites Veblen 1904 and Hilbert 1903] For most mathematicians, categorical axiomatisation is the best you can ever dream of (rather than a single true axiomatisation). |
21470 | For me the objective thing-in-itself is the will [Schopenhauer] |
Full Idea: Thing in itself signifies that which exists independently of our perception, that which actually is; …to Kant it was '= x'; to me it is will. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], IV:61) | |
A reaction: Does he mean his own will, which is plausible since he has direct experience of it, or is he referring will in general - whatever that is? |
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) |
21479 | Knowledge is not power! Ignorant people possess supreme authority [Schopenhauer] |
Full Idea: Knowledge is power. The devil it is! One man can have a great deal of knowledge without its giving him the least power, while another possesses supreme authority but next to no knowledge. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], III:43) | |
A reaction: He is referring to Bacon's famous adage. Bacon may be right about military affairs, but not about politics. |
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. |
21476 | A priori propositions are those we could never be seriously motivated to challenge [Schopenhauer] |
Full Idea: A dictate of reason is the name we give to certain propositions which we hold to be true without investigation, and of which we think ourselves so firmly convinced we should be incapable of seriously testing them even if we wanted to. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], I:12) | |
A reaction: This is closer to the cautious way modern thinkers are inclined to express the idea. Even Quine would be reasonably happy with this. |
21473 | All knowledge and explanation rests on the inexplicable [Schopenhauer] |
Full Idea: The fundament upon which all our knowledge and learning rests is the inexplicable. It is to this that every explanation, through few or many intermediary stages, leads. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], I:1) | |
A reaction: This is obviously true, and the only question is whether it is a necessary or a contingent truth. |
21478 | Half our thinking is unconscious, and we reach conclusions while unaware of premises [Schopenhauer] |
Full Idea: One might almost believe that half our thinking takes place unconsciously.. Usually we arrive at a conclusion without having clearly thought about the premises which lead to it. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], III:40) | |
A reaction: Schopenhauer was a major pioneer of this crucial idea. I'm beginning to think it is much greater than a half. |
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) |
21477 | We don't control our own thinking [Schopenhauer] |
Full Idea: Thoughts come not when we want but when they want. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], III:37) | |
A reaction: One of my favourite Nietzsche ideas originated in Schopenhauer! |
21475 | All of our concepts are borrowed from perceptual knowledge [Schopenhauer] |
Full Idea: The entire property of a concept consists in nothing more than what has been begged and borrowed from perceptual knowledge, which is the true and inexhaustible source of all insight. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], I:9) | |
A reaction: Schopenhauer is usually seen as a sort of idealist, but this is a full endorsement of the empirical view of concepts, to which I largely subscribe. Note that he talks of 'knowledge', rather than of 'experience'. |
18762 | A maxim claims that if we are allowed to assert a sentence, that means it must be true [McGee] |
Full Idea: If our linguistic conventions entitle us to assert a sentence, they thereby make it true, because of the maxim that 'truth is the norm of assertion'. | |
From: Vann McGee (Logical Consequence [2014], 8) | |
A reaction: You could only really deny that maxim if you had no belief at all in truth, but then you can assert anything you like (with full entitlement). Maybe you can assert anything you like as long as it doesn't upset anyone? Etc. |
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) |
21372 | Aesthetics concerns how we can take pleasure in an object, with no reference to the will [Schopenhauer] |
Full Idea: The central problem of aesthetics is how satisfaction with and pleasure in an object are possible without any reference thereof to our willing. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], II:415), quoted by Christopher Janaway - Schopenhauer 6 'Aesthetic' | |
A reaction: This does seem a good distinction. We can divide pleasures into willed and unwilled. Compare thinking that some remote stranger (in a photograph) is very beautiful, with falling in love with someone. |
21488 | The beautiful is a perception of Plato's Forms, which eliminates the will [Schopenhauer] |
Full Idea: In the beautiful we always perceive the intrinsic and primary form of animate and inanimate nature, that is to say Plato's Ideas thereof. …When an aesthetic perception occurs the will completely vanishes from consciousness. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XIX:205) | |
A reaction: An essential Schopenauer idea. Iris Murdoch said something similar. |
21483 | Man is essentially a dreadful wild animal [Schopenhauer] |
Full Idea: Man is at bottom a dreadful wild animal. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], VIII:114) | |
A reaction: As an example he cites the slave owners in the United States. |
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. |
21466 | Pleasure is weaker, and pain stronger, than we expect [Schopenhauer] |
Full Idea: As a rule we find pleasure much less pleasurable, pain much more painful than we expected. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XII:149) | |
A reaction: Never go on holiday with Schopenhauer. This is more accurate about pain, I think. |
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) |
21484 | A man's character can be learned from a single characteristic action [Schopenhauer] |
Full Idea: As a botanist can recognise the whole plant from one leaf, …so an accurate knowledge of a man's character can be arrived at from a single characteristic action. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], VIII:118) | |
A reaction: Very true. Great novelists specialise in such observations. One word can reveal a character, as well as one action. |
21482 | The five Chinese virtues: pity, justice, politeness, wisdom, honesty [Schopenhauer] |
Full Idea: The Chinese name five cardinal virtues: pity, justice, politeness, wisdom and honesty. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], VIII:110) | |
A reaction: I like politeness being on the list, though it seems rather superficial to be a virtue of character. Respect would be better. |
21481 | Buddhists wisely start with the cardinal vices [Schopenhauer] |
Full Idea: Because of their profounder ethical and metaphysical insight, the Buddhists start not with the cardinal virtues but with cardinal vices, …which are lust, sloth, wrath and avarice (and maybe hatred). | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], VIII:110) | |
A reaction: This may be right. Our lives are affected much more by the vices of others than by their virtues, and most virtuous behaviour aims at rectifying the bad effects of other people's vices. |
21480 | Boredom is only felt by those clever enough to need activity [Schopenhauer] |
Full Idea: Only in the cleverest animals such as dogs and apes does the need for activity, and with that boredom, make itself felt. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], III:50) | |
A reaction: But it is much more frequently young creatures, of almost any kind, that seek constant activity, and get continually restless. The most active adults need not be the cleverest. |
21469 | Human life is a mistake, shown by boredom, which is direct awareness of the fact [Schopenhauer] |
Full Idea: Human life must be some kind of mistake. ...Boredom is a direct proof that existence is in itself valueless, for boredom is nothing other than the sensation of the emptiness of existence. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XI:146) | |
A reaction: I think it is a good advertisement for existentialism that it makes something more out of boredom than Schopenhauer does. |
21485 | The state only exists to defend citizens, from exterior threats, and from one another [Schopenhauer] |
Full Idea: The state is essentially no more than an institution for the protection of the whole against attacks from without, and the protection of its individual members from attacks by one another. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], IX:123) | |
A reaction: He then has a swipe at Hegel for his inflated idea of the importance of the state. Schopenhauer is close to Hobbes on this one. |
21486 | Poverty and slavery are virtually two words for the same thing [Schopenhauer] |
Full Idea: Poverty and slavery are only two forms - on might almost say two words for - the same thing, the essence of which is that a man's energies are expended for the most part not on his own behalf but on that of others. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], IX:125) | |
A reaction: The modern world is full of people who righteously despise slavery, but think only of the poor that it serves them right. |
21487 | The freedom of the press to sell poison outweighs its usefulness [Schopenhauer] |
Full Idea: Freedom of the press must be regarded as a permit to sell poison. …I very much fear, therefore, that the dangers of press freedom outweigh its usefulness. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], IX:127) | |
A reaction: On the whole the modern world disagrees with this view, but watching the popular press in Britain in the last twenty years has made me sympathise with Schopenhauer. |
21471 | If suicide was quick and easy, most people would have done it by now [Schopenhauer] |
Full Idea: Perhaps there is no one alive who would not already have put an end to his life if this end were something purely negative, a sudden cessation of existence. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XIII:158) | |
A reaction: Nonsense, on the whole, but it is a nice question how many people would do it if it only took a painless instant. |
21467 | Would humanity still exist if sex wasn't both desired and pleasurable? [Schopenhauer] |
Full Idea: If the act of procreation were neither the outcome of a desire nor accompanied by feelings of pleasure, but a matter to be decided on the basis of purely rational considerations, is it likely the human race would still exist? | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XII:156) | |
A reaction: This is almost certainly correct in the modern world. In tougher economic circumstances people seem desperate to have children who will help them survive. |
21472 | Only religion introduces serious issues to uneducated people [Schopenhauer] |
Full Idea: Religion is the only means of introducing some notion of the high significance of life into the uncultivated heads of the masses. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XV:174) | |
A reaction: Cf Philip Larkin's poem 'Church Going'. On the whole Schopenhauer didn't actually believe that our lives had any 'high significance'. |
21468 | The Creator created the possibilities for worlds, so should have made a better one than this possible [Schopenhauer] |
Full Idea: The Creator created not only the world, but also created possibility itself; therefore he should have created the possibility of a better world than this one. | |
From: Arthur Schopenhauer (Parerga and Paralipomena [1851], XII:156) | |
A reaction: This is explicitly a response to Leibniz's claim that the Creator selected the best of all possible worlds from the available options. The Euthyphro Question hovers here: must the Creator accept what is possible (the platonic view), or create possibility? |