66 ideas
19441 | All philosophies presuppose their historical moment, and arise from it [Feuerbach] |
19456 | Philosophy is distinguished from other sciences by its complete lack of presuppositions [Feuerbach] |
19442 | I don't study Plato for his own sake; the primary aim is always understanding [Feuerbach] |
6928 | Only that which can be an object of religion is an object of philosophy [Feuerbach] |
6918 | Philosophy should not focus on names, but on the determined nature of things [Feuerbach] |
6904 | Modern philosophy begins with Descartes' abstraction from sensation and matter [Feuerbach] |
6931 | Empiricism is right about ideas, but forgets man himself as one of our objects [Feuerbach] |
1403 | A rational donkey would starve to death between two totally identical piles of hay [Buridan, by PG] |
6933 | The laws of reality are also the laws of thought [Feuerbach] |
19444 | Each proposition has an antithesis, and truth exists as its refutation [Feuerbach] |
19445 | A dialectician has to be his own opponent [Feuerbach] |
19443 | Truth forges an impersonal unity between people [Feuerbach] |
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] |
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] |
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] |
6919 | Absolute thought remains in another world from being [Feuerbach] |
19457 | Being is what is undetermined, and hence indistinguishable [Feuerbach] |
6920 | Being posits essence, and my essence is my being [Feuerbach] |
6921 | Particularity belongs to being, whereas generality belongs to thought [Feuerbach] |
6926 | The only true being is of the senses, perception, feeling and love [Feuerbach] |
19446 | To our consciousness it is language which looks unreal [Feuerbach] |
16678 | Without magnitude a thing would retain its parts, but they would have no location [Buridan] |
16793 | A thing is (less properly) the same over time if each part is succeeded by another [Buridan] |
6908 | Consciousness is absolute reality, and everything exists through consciousness [Feuerbach] |
19447 | The Absolute is the 'and' which unites 'spirit and nature' [Feuerbach] |
6932 | Ideas arise through communication, and reason is reached through community [Feuerbach] |
16726 | Why can't we deduce secondary qualities from primary ones, if they cause them? [Buridan] |
6935 | In man the lowest senses of smell and taste elevate themselves to intellectual acts [Feuerbach] |
16577 | Induction is not demonstration, because not all of the instances can be observed [Buridan] |
16576 | Science is based on induction, for general truths about fire, rhubarb and magnets [Buridan] |
19451 | When absorbed in deep reflection, is your reason in control, or is it you? [Feuerbach] |
6925 | The new philosophy thinks of the concrete in a concrete (not a abstract) manner [Feuerbach] |
6924 | Plotinus was ashamed to have a body [Feuerbach] |
6927 | If you love nothing, it doesn't matter whether something exists or not [Feuerbach] |
19450 | Reason, love and will are the highest perfections and essence of man - the purpose of his life [Feuerbach] |
19458 | Egoism is the only evil, love the only good; genuine love produces all the other virtues [Feuerbach] |
6934 | Man is not a particular being, like animals, but a universal being [Feuerbach] |
6936 | The essence of man is in community, but with distinct individuals [Feuerbach] |
19448 | Consciousness is said to distinguish man from animals - consciousness of his own species [Feuerbach] |
19454 | A God needs justice, kindness and wisdom, but those concepts don't depend on the concept of God [Feuerbach] |
6913 | God's existence cannot be separated from essence and concept, which can only be thought as existing [Feuerbach] |
19452 | The nature of God is an expression of human nature [Feuerbach] |
6903 | If God is only an object for man, then only the essence of man is revealed in God [Feuerbach] |
6923 | God is what man would like to be [Feuerbach] |
6911 | God is for us a mere empty idea, which we fill with our own ego and essence [Feuerbach] |
19453 | If love, goodness and personality are human, the God who is their source is anthropomorphic [Feuerbach] |
6902 | Catholicism concerns God in himself, Protestantism what God is for man [Feuerbach] |
19449 | Religion is the consciousness of the infinite [Feuerbach] |
6905 | Absolute idealism is the realized divine mind of Leibnizian theism [Feuerbach] |
19455 | Today's atheism will tomorrow become a religion [Feuerbach] |