151 ideas
21916 | Philosophers can't be religious, and don't need to be; philosophy is perilous but free [Schopenhauer] |
4171 | Philosophy considers only the universal, in nature as everywhere else [Schopenhauer] |
4186 | Everyone is conscious of all philosophical truths, but philosophers bring them to conceptual awareness [Schopenhauer] |
12171 | Absurdity is incongruity between correct and false points of view [Schopenhauer] |
21366 | Metaphysics must understand the world thoroughly, as a principal source of knowledge [Schopenhauer] |
21474 | Metaphysics studies the inexplicable ends of explanation [Schopenhauer] |
21918 | Sufficient Reason can't be proved, because all proof presupposes it [Schopenhauer, by Lewis,PB] |
4187 | 'There is nothing without a reason why it should be rather than not be' (a generalisation of 'Why?') [Schopenhauer] |
8721 | An 'impredicative' definition seems circular, because it uses the term being defined [Friend] |
8680 | Classical definitions attempt to refer, but intuitionist/constructivist definitions actually create objects [Friend] |
3678 | Reductio ad absurdum proves an idea by showing that its denial produces contradiction [Friend] |
8705 | Anti-realists see truth as our servant, and epistemically contrained [Friend] |
8713 | In classical/realist logic the connectives are defined by truth-tables [Friend] |
8708 | Double negation elimination is not valid in intuitionist logic [Friend] |
8694 | Free logic was developed for fictional or non-existent objects [Friend] |
8665 | A 'proper subset' of A contains only members of A, but not all of them [Friend] |
8672 | A 'powerset' is all the subsets of a set [Friend] |
8677 | Set theory makes a minimum ontological claim, that the empty set exists [Friend] |
8666 | Infinite sets correspond one-to-one with a subset [Friend] |
8682 | Major set theories differ in their axioms, and also over the additional axioms of choice and infinity [Friend] |
8709 | The law of excluded middle is syntactic; it just says A or not-A, not whether they are true or false [Friend] |
8711 | Intuitionists read the universal quantifier as "we have a procedure for checking every..." [Friend] |
8675 | Paradoxes can be solved by talking more loosely of 'classes' instead of 'sets' [Friend] |
8674 | The Burali-Forti paradox asks whether the set of all ordinals is itself an ordinal [Friend] |
8667 | The 'integers' are the positive and negative natural numbers, plus zero [Friend] |
8668 | The 'rational' numbers are those representable as fractions [Friend] |
8670 | A number is 'irrational' if it cannot be represented as a fraction [Friend] |
8661 | The natural numbers are primitive, and the ordinals are up one level of abstraction [Friend] |
8664 | Cardinal numbers answer 'how many?', with the order being irrelevant [Friend] |
8671 | The 'real' numbers (rationals and irrationals combined) is the Continuum, which has no gaps [Friend] |
8663 | Raising omega to successive powers of omega reveal an infinity of infinities [Friend] |
8662 | The first limit ordinal is omega (greater, but without predecessor), and the second is twice-omega [Friend] |
8669 | Between any two rational numbers there is an infinite number of rational numbers [Friend] |
8676 | Is mathematics based on sets, types, categories, models or topology? [Friend] |
8678 | Most mathematical theories can be translated into the language of set theory [Friend] |
8701 | The number 8 in isolation from the other numbers is of no interest [Friend] |
8702 | In structuralism the number 8 is not quite the same in different structures, only equivalent [Friend] |
8699 | Are structures 'ante rem' (before reality), or are they 'in re' (grounded in physics)? [Friend] |
8696 | Structuralist says maths concerns concepts about base objects, not base objects themselves [Friend] |
8695 | Structuralism focuses on relations, predicates and functions, with objects being inessential [Friend] |
8700 | 'In re' structuralism says that the process of abstraction is pattern-spotting [Friend] |
8681 | The big problem for platonists is epistemic: how do we perceive, intuit, know or detect mathematical facts? [Friend] |
8712 | Mathematics should be treated as true whenever it is indispensable to our best physical theory [Friend] |
8716 | Formalism is unconstrained, so cannot indicate importance, or directions for research [Friend] |
8706 | Constructivism rejects too much mathematics [Friend] |
8707 | Intuitionists typically retain bivalence but reject the law of excluded middle [Friend] |
4168 | Matter and intellect are inseparable correlatives which only exist relatively, and for each other [Schopenhauer] |
458 | Nothing could come out of nothing, and existence could never completely cease [Empedocles] |
5112 | Empedocles says things are at rest, unless love unites them, or hatred splits them [Empedocles, by Aristotle] |
21470 | For me the objective thing-in-itself is the will [Schopenhauer] |
21926 | Schopenhauer, unlike other idealists, says reality is irrational [Schopenhauer, by Lewis,PB] |
4167 | The knowing subject and the crude matter of the world are both in themselves unknowable [Schopenhauer] |
21920 | No need for a priori categories, since sufficient reason shows the interrelations [Schopenhauer, by Lewis,PB] |
8704 | Structuralists call a mathematical 'object' simply a 'place in a structure' [Friend] |
13209 | There is no coming-to-be of anything, but only mixing and separating [Empedocles, by Aristotle] |
457 | Substance is not created or destroyed in mortals, but there is only mixing and exchange [Empedocles] |
21362 | Necessity is physical, logical, mathematical or moral [Schopenhauer, by Janaway] |
4192 | All necessity arises from causation, which is conditioned; there is no absolute or unconditioned necessity [Schopenhauer] |
4190 | All understanding is an immediate apprehension of the causal relation [Schopenhauer] |
21479 | Knowledge is not power! Ignorant people possess supreme authority [Schopenhauer] |
4165 | Descartes found the true beginning of philosophy with the Cogito, in the consciousness of the individual [Schopenhauer] |
21361 | For Schopenhauer, material things would not exist without the mind [Schopenhauer, by Janaway] |
21923 | Schopenhauer can't use force/energy instead of 'will', because he is not a materialist [Lewis,PB on Schopenhauer] |
4162 | The world only exists in relation to something else, as an idea of the one who conceives it [Schopenhauer] |
21922 | We know reality because we know our own bodies and actions [Schopenhauer] |
21913 | Kant rightly separates appearance and thing-in-itself [Schopenhauer] |
21919 | Object for a subject and representation are the same thing [Schopenhauer] |
21476 | A priori propositions are those we could never be seriously motivated to challenge [Schopenhauer] |
4164 | Direct feeling of the senses are merely data; perception of the world comes with understanding causes [Schopenhauer] |
4163 | All perception is intellectual [Schopenhauer] |
462 | One vision is produced by both eyes [Empedocles] |
21473 | All knowledge and explanation rests on the inexplicable [Schopenhauer] |
21917 | The four explanations: objects by causes, concepts by ground, maths by spacetime, ethics by motive [Schopenhauer, by Lewis,PB] |
4166 | A consciousness without an object is no consciousness [Schopenhauer] |
21369 | We have hidden and unadmitted desires and fears, suppressed because of vanity [Schopenhauer] |
21478 | Half our thinking is unconscious, and we reach conclusions while unaware of premises [Schopenhauer] |
4191 | What we know in ourselves is not a knower but a will [Schopenhauer] |
21367 | I know both aspects of my body, as representation, and as will [Schopenhauer] |
21368 | The knot of the world is the use of 'I' to refer to both willing and knowing [Schopenhauer] |
4175 | It is as perverse to resent our individuality being replaced by others, as to resent the body renewing itself [Schopenhauer] |
4176 | We all regard ourselves a priori as free, but see from experience that character and motive compel us [Schopenhauer] |
21477 | We don't control our own thinking [Schopenhauer] |
4170 | Man's actions are not free, because they follow strictly from impact of motive on character [Schopenhauer] |
22765 | Wisdom and thought are shared by all things [Empedocles] |
8685 | Studying biology presumes the laws of chemistry, and it could never contradict them [Friend] |
1524 | For Empedocles thinking is almost identical to perception [Empedocles, by Theophrastus] |
8688 | Concepts can be presented extensionally (as objects) or intensionally (as a characterization) [Friend] |
21921 | Concepts are abstracted from perceptions [Schopenhauer, by Lewis,PB] |
21475 | All of our concepts are borrowed from perceptual knowledge [Schopenhauer] |
4169 | Every true act of will is also at once and without exception a movement of the body [Schopenhauer] |
7187 | Schopenhauer was caught in Christian ideals, because he didn't deify his 'will' [Nietzsche on Schopenhauer] |
21365 | Only the will is thing-in-itself, seen both in blind nature and in human action [Schopenhauer] |
21924 | As the subject of willing I am wretched, but absorption in knowledge is bliss [Schopenhauer] |
4173 | If we were essentially intellect rather than will, our moral worth would depend on imagined motives [Schopenhauer] |
21363 | Motivation is causality seen from within [Schopenhauer] |
21372 | Aesthetics concerns how we can take pleasure in an object, with no reference to the will [Schopenhauer] |
21370 | Schopenhauer is a chief proponent of aesthetic experience as 'disinterested' [Schopenhauer, by Janaway] |
4182 | A principal pleasure of the beautiful is that it momentarily silences the will [Schopenhauer] |
21488 | The beautiful is a perception of Plato's Forms, which eliminates the will [Schopenhauer] |
21928 | The Sublime fights for will-less knowing, when faced with a beautiful threat to humanity [Schopenhauer, by Lewis,PB] |
21927 | Schopenhauer emphasises Ideas in art, unlike most romantics [Schopenhauer, by Lewis,PB] |
8116 | The will-less contemplation of art brings a liberation from selfhood [Schopenhauer, by Gardner] |
4174 | Man is more beautiful than anything else, and the loftiest purpose of art is to reveal his nature [Schopenhauer] |
21380 | The only aim of our existence is to grasp that non-existence would be better [Schopenhauer] |
21374 | We should no more expect ethical theory to produce good people than aesthetics to produce artists [Schopenhauer] |
21378 | We clearly feel responsible for our deeds, because we are quite certain that we did them [Schopenhauer] |
21375 | Reason can be vicious, and great crimes have to be rational [Schopenhauer] |
21915 | To deduce morality from reason is blasphemy, because it is holy, and far above reason [Schopenhauer] |
21483 | Man is essentially a dreadful wild animal [Schopenhauer] |
21379 | Man's three basic ethical incentives are egoism, malice and compassion [Schopenhauer] |
4181 | Every good is essentially relative, for it has its essential nature only in its relation to a desiring will [Schopenhauer] |
5649 | Will casts aside each of its temporary fulfilments, so human life has no ultimate aim [Schopenhauer, by Scruton] |
4177 | Most people would probably choose non-existence at the end of their life, rather than relive the whole thing [Schopenhauer] |
4185 | Altruistic people make less distinction than usual between themselves and others [Schopenhauer] |
4183 | Only self-love can motivate morality, but that also makes it worthless [Schopenhauer] |
552 | Empedocles said good and evil were the basic principles [Empedocles, by Aristotle] |
4172 | Happiness is the swift movement from desire to satisfaction, and then again on to desire [Schopenhauer] |
21371 | We can never attain happiness while our will is pursuing desires [Schopenhauer] |
21466 | Pleasure is weaker, and pain stronger, than we expect [Schopenhauer] |
4184 | Virtue must spring from an intuitive recognition that other people are essentially like us [Schopenhauer] |
21484 | A man's character can be learned from a single characteristic action [Schopenhauer] |
21482 | The five Chinese virtues: pity, justice, politeness, wisdom, honesty [Schopenhauer] |
21481 | Buddhists wisely start with the cardinal vices [Schopenhauer] |
21480 | Boredom is only felt by those clever enough to need activity [Schopenhauer] |
21469 | Human life is a mistake, shown by boredom, which is direct awareness of the fact [Schopenhauer] |
21485 | The state only exists to defend citizens, from exterior threats, and from one another [Schopenhauer] |
21486 | Poverty and slavery are virtually two words for the same thing [Schopenhauer] |
21487 | The freedom of the press to sell poison outweighs its usefulness [Schopenhauer] |
21471 | If suicide was quick and easy, most people would have done it by now [Schopenhauer] |
21467 | Would humanity still exist if sex wasn't both desired and pleasurable? [Schopenhauer] |
21376 | Philosophy treats animals as exploitable things, ignoring the significance of their lives [Schopenhauer] |
589 | 'Nature' is just a word invented by people [Empedocles] |
4179 | The essence of nature is the will to life itself [Schopenhauer] |
21823 | The principle of 'Friendship' in Empedocles is the One, and is bodiless [Empedocles, by Plotinus] |
2680 | Empedocles said that there are four material elements, and two further creative elements [Empedocles, by Aristotle] |
6002 | Empedocles says bone is water, fire and earth in ratio 2:4:2 [Empedocles, by Inwood] |
13207 | Fire, Water, Air and Earth are elements, being simple as well as homoeomerous [Empedocles, by Aristotle] |
459 | All change is unity through love or division through hate [Empedocles] |
13218 | The elements combine in coming-to-be, but how do the elements themselves come-to-be? [Aristotle on Empedocles] |
13225 | Love and Strife only explain movement if their effects are distinctive [Aristotle on Empedocles] |
460 | If the one Being ever diminishes it would no longer exist, and what could ever increase it? [Empedocles] |
4189 | Time may be defined as the possibility of mutually exclusive conditions of the same thing [Schopenhauer] |
5090 | Maybe bodies are designed by accident, and the creatures that don't work are destroyed [Empedocles, by Aristotle] |
466 | God is pure mind permeating the universe [Empedocles] |
461 | God is a pure, solitary, and eternal sphere [Empedocles] |
1719 | In Empedocles' theory God is ignorant because, unlike humans, he doesn't know one of the elements (strife) [Aristotle on Empedocles] |
1522 | It is wretched not to want to think clearly about the gods [Empedocles] |
4178 | Christianity is a pessimistic religion, in which the world is equated with evil [Schopenhauer] |
4180 | Religion is the mythical clothing of the truth which is inaccessible to the crude human intellect [Schopenhauer] |
21472 | Only religion introduces serious issues to uneducated people [Schopenhauer] |
21468 | The Creator created the possibilities for worlds, so should have made a better one than this possible [Schopenhauer] |