85 ideas
14888 | Wisdom prevents us from being ruled by the moment [Nietzsche] |
14863 | Unlike science, true wisdom involves good taste [Nietzsche] |
14890 | Suffering is the meaning of existence [Nietzsche] |
14861 | Philosophy ennobles the world, by producing an artistic conception of our knowledge [Nietzsche] |
14885 | The first aim of a philosopher is a life, not some works [Nietzsche] |
14887 | You should only develop a philosophy if you are willing to live by it [Nietzsche] |
14889 | Philosophy is pointless if it does not advocate, and live, a new way of life [Nietzsche] |
14862 | Philosophy is more valuable than much of science, because of its beauty [Nietzsche] |
14878 | It would better if there was no thought [Nietzsche] |
14881 | Why do people want philosophers? [Nietzsche] |
14876 | Philosophy is always secondary, because it cannot support a popular culture [Nietzsche] |
14860 | Kant has undermined our belief in metaphysics [Nietzsche] |
14859 | If philosophy controls science, then it has to determine its scope, and its value [Nietzsche] |
224 | When questions are doubtful we should concentrate not on objects but on ideas of the intellect [Plato] |
232 | Opposites are as unlike as possible [Plato] |
8937 | Plato's 'Parmenides' is the greatest artistic achievement of the ancient dialectic [Hegel on Plato] |
13520 | A 'tautology' must include connectives [Wolf,RS] |
13524 | Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof [Wolf,RS] |
13522 | Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS] |
13521 | Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS] |
13523 | Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS] |
13529 | Empty Set: ∃x∀y ¬(y∈x). The unique empty set exists [Wolf,RS] |
13526 | Comprehension Axiom: if a collection is clearly specified, it is a set [Wolf,RS] |
14880 | Logic is just slavery to language [Nietzsche] |
13534 | In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS] |
13535 | First-order logic is weakly complete (valid sentences are provable); we can't prove every sentence or its negation [Wolf,RS] |
13531 | Model theory reveals the structures of mathematics [Wolf,RS] |
13532 | Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS] |
13519 | Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS] |
13533 | First-order model theory rests on completeness, compactness, and the Löwenheim-Skolem-Tarski theorem [Wolf,RS] |
13537 | An 'isomorphism' is a bijection that preserves all structural components [Wolf,RS] |
13539 | The LST Theorem is a serious limitation of first-order logic [Wolf,RS] |
13538 | If a theory is complete, only a more powerful language can strengthen it [Wolf,RS] |
13525 | Most deductive logic (unlike ordinary reasoning) is 'monotonic' - we don't retract after new givens [Wolf,RS] |
13986 | Plato found antinomies in ideas, Kant in space and time, and Bradley in relations [Plato, by Ryle] |
14150 | Plato's 'Parmenides' is perhaps the best collection of antinomies ever made [Russell on Plato] |
13530 | An ordinal is an equivalence class of well-orderings, or a transitive set whose members are transitive [Wolf,RS] |
13518 | Modern mathematics has unified all of its objects within set theory [Wolf,RS] |
16150 | One is, so numbers exist, so endless numbers exist, and each one must partake of being [Plato] |
229 | The one was and is and will be and was becoming and is becoming and will become [Plato] |
21821 | Plato's Parmenides has a three-part theory, of Primal One, a One-Many, and a One-and-Many [Plato, by Plotinus] |
14869 | If some sort of experience is at the root of matter, then human knowledge is close to its essence [Nietzsche] |
221 | Absolute ideas, such as the Good and the Beautiful, cannot be known by us [Plato] |
227 | You must always mean the same thing when you utter the same name [Plato] |
223 | If you deny that each thing always stays the same, you destroy the possibility of discussion [Plato] |
211 | If admirable things have Forms, maybe everything else does as well [Plato] |
219 | If absolute ideas existed in us, they would cease to be absolute [Plato] |
228 | Greatness and smallness must exist, to be opposed to one another, and come into being in things [Plato] |
16151 | Plato moves from Forms to a theory of genera and principles in his later work [Plato, by Frede,M] |
210 | It would be absurd to think there were abstract Forms for vile things like hair, mud and dirt [Plato] |
220 | The concept of a master includes the concept of a slave [Plato] |
218 | Participation is not by means of similarity, so we are looking for some other method of participation [Plato] |
212 | The whole idea of each Form must be found in each thing which participates in it [Plato] |
213 | Each idea is in all its participants at once, just as daytime is a unity but in many separate places at once [Plato] |
216 | If things are made alike by participating in something, that thing will be the absolute idea [Plato] |
215 | If things partake of ideas, this implies either that everything thinks, or that everything actually is thought [Plato] |
214 | If absolute greatness and great things are seen as the same, another thing appears which makes them seem great [Plato] |
217 | Nothing can be like an absolute idea, because a third idea intervenes to make them alike (leading to a regress) [Plato] |
15851 | Parts must belong to a created thing with a distinct form [Plato] |
15846 | In Parmenides, if composition is identity, a whole is nothing more than its parts [Plato, by Harte,V] |
15849 | Plato says only a one has parts, and a many does not [Plato, by Harte,V] |
15850 | Anything which has parts must be one thing, and parts are of a one, not of a many [Plato] |
13259 | It seems that the One must be composed of parts, which contradicts its being one [Plato] |
15847 | Two things relate either as same or different, or part of a whole, or the whole of the part [Plato] |
14875 | Belief matters more than knowledge, and only begins when knowledge ceases [Nietzsche] |
14866 | It always remains possible that the world just is the way it appears [Nietzsche] |
14872 | Our knowledge is illogical, because it rests on false identities between things [Nietzsche] |
14879 | The most extreme scepticism is when you even give up logic [Nietzsche] |
14873 | If we find a hypothesis that explains many things, we conclude that it explains everything [Nietzsche] |
14868 | Our primary faculty is perception of structure, as when looking in a mirror [Nietzsche] |
14870 | We experience causation between willing and acting, and thereby explain conjunctions of changes [Nietzsche] |
14867 | It is just madness to think that the mind is supernatural (or even divine!) [Nietzsche] |
14884 | The shortest path to happiness is forgetfulness, the path of animals (but of little value) [Nietzsche] |
14886 | Education is contrary to human nature [Nietzsche] |
222 | Only a great person can understand the essence of things, and an even greater person can teach it [Plato] |
14883 | We should evaluate the past morally [Nietzsche] |
14882 | Protest against vivisection - living things should not become objects of scientific investigation [Nietzsche] |
225 | The unlimited has no shape and is endless [Plato] |
233 | Some things do not partake of the One [Plato] |
2062 | The only movement possible for the One is in space or in alteration [Plato] |
231 | Everything partakes of the One in some way [Plato] |
14865 | We do not know the nature of one single causality [Nietzsche] |
14871 | Laws of nature are merely complex networks of relations [Nietzsche] |
234 | We couldn't discuss the non-existence of the One without knowledge of it [Plato] |
14864 | The Greeks lack a normative theology: each person has their own poetic view of things [Nietzsche] |