71 ideas
18730 | The history of philosophy only matters if the subject is a choice between rival theories [Wittgenstein] |
18704 | Philosophy tries to be rid of certain intellectual puzzles, irrelevant to daily life [Wittgenstein] |
18710 | Philosophers express puzzlement, but don't clearly state the puzzle [Wittgenstein] |
18732 | We don't need a theory of truth, because we use the word perfectly well [Wittgenstein] |
18714 | We already know what we want to know, and analysis gives us no new facts [Wittgenstein] |
17774 | Definitions make our intuitions mathematically useful [Mayberry] |
17773 | Proof shows that it is true, but also why it must be true [Mayberry] |
18706 | Words of the same kind can be substituted in a proposition without producing nonsense [Wittgenstein] |
18735 | Talking nonsense is not following the rules [Wittgenstein] |
18719 | Grammar says that saying 'sound is red' is not false, but nonsense [Wittgenstein] |
18731 | There is no theory of truth, because it isn't a concept [Wittgenstein] |
18707 | All thought has the logical form of reality [Wittgenstein] |
17795 | Set theory can't be axiomatic, because it is needed to express the very notion of axiomatisation [Mayberry] |
17796 | There is a semi-categorical axiomatisation of set-theory [Mayberry] |
17800 | The misnamed Axiom of Infinity says the natural numbers are finite in size [Mayberry] |
17801 | The set hierarchy doesn't rely on the dubious notion of 'generating' them [Mayberry] |
17803 | Limitation of size is part of the very conception of a set [Mayberry] |
18724 | In logic nothing is hidden [Wittgenstein] |
17786 | The mainstream of modern logic sees it as a branch of mathematics [Mayberry] |
17788 | First-order logic only has its main theorems because it is so weak [Mayberry] |
17791 | Only second-order logic can capture mathematical structure up to isomorphism [Mayberry] |
18709 | Laws of logic are like laws of chess - if you change them, it's just a different game [Wittgenstein] |
18736 | Contradiction is between two rules, not between rule and reality [Wittgenstein] |
18723 | We may correctly use 'not' without making the rule explicit [Wittgenstein] |
18718 | Saying 'and' has meaning is just saying it works in a sentence [Wittgenstein] |
18727 | A person's name doesn't mean their body; bodies don't sit down, and their existence can be denied [Wittgenstein] |
17787 | Big logic has one fixed domain, but standard logic has a domain for each interpretation [Mayberry] |
17790 | No Löwenheim-Skolem logic can axiomatise real analysis [Mayberry] |
17779 | 'Classificatory' axioms aim at revealing similarity in morphology of structures [Mayberry] |
17778 | Axiomatiation relies on isomorphic structures being essentially the same [Mayberry] |
17780 | 'Eliminatory' axioms get rid of traditional ideal and abstract objects [Mayberry] |
17789 | No logic which can axiomatise arithmetic can be compact or complete [Mayberry] |
18738 | We don't get 'nearer' to something by adding decimals to 1.1412... (root-2) [Wittgenstein] |
17784 | Real numbers can be eliminated, by axiom systems for complete ordered fields [Mayberry] |
17782 | Greek quantities were concrete, and ratio and proportion were their science [Mayberry] |
17781 | Real numbers were invented, as objects, to simplify and generalise 'quantity' [Mayberry] |
17799 | Cantor's infinite is an absolute, of all the sets or all the ordinal numbers [Mayberry] |
17797 | Cantor extended the finite (rather than 'taming the infinite') [Mayberry] |
18708 | Infinity is not a number, so doesn't say how many; it is the property of a law [Wittgenstein] |
17775 | If proof and definition are central, then mathematics needs and possesses foundations [Mayberry] |
17776 | The ultimate principles and concepts of mathematics are presumed, or grasped directly [Mayberry] |
17777 | Foundations need concepts, definition rules, premises, and proof rules [Mayberry] |
17804 | Axiom theories can't give foundations for mathematics - that's using axioms to explain axioms [Mayberry] |
17792 | 1st-order PA is only interesting because of results which use 2nd-order PA [Mayberry] |
17793 | It is only 2nd-order isomorphism which suggested first-order PA completeness [Mayberry] |
17794 | Set theory is not just first-order ZF, because that is inadequate for mathematics [Mayberry] |
17802 | We don't translate mathematics into set theory, because it comes embodied in that way [Mayberry] |
17805 | Set theory is not just another axiomatised part of mathematics [Mayberry] |
18737 | There are no positive or negative facts; these are just the forms of propositions [Wittgenstein] |
18715 | Using 'green' is a commitment to future usage of 'green' [Wittgenstein] |
17785 | Real numbers as abstracted objects are now treated as complete ordered fields [Mayberry] |
18726 | For each necessity in the world there is an arbitrary rule of language [Wittgenstein] |
18712 | Understanding is translation, into action or into other symbols [Wittgenstein] |
18280 | We live in sense-data, but talk about physical objects [Wittgenstein] |
18729 | Part of what we mean by stating the facts is the way we tend to experience them [Wittgenstein] |
18734 | If you remember wrongly, then there must be some other criterion than your remembering [Wittgenstein] |
18721 | Explanation and understanding are the same [Wittgenstein] |
18720 | Explanation gives understanding by revealing the full multiplicity of the thing [Wittgenstein] |
18716 | A machine strikes us as being a rule of movement [Wittgenstein] |
18713 | If an explanation is good, the symbol is used properly in the future [Wittgenstein] |
7658 | Obviously there can't be a functional anaylsis of qualia if they are defined by intrinsic properties [Dennett] |
7655 | The work done by the 'homunculus in the theatre' must be spread amongst non-conscious agencies [Dennett] |
7657 | Intelligent agents are composed of nested homunculi, of decreasing intelligence, ending in machines [Dennett] |
7656 | I don't deny consciousness; it just isn't what people think it is [Dennett] |
18717 | Thought is an activity which we perform by the expression of it [Wittgenstein] |
7654 | What matters about neuro-science is the discovery of the functional role of the chemistry [Dennett] |
18725 | A proposition draws a line around the facts which agree with it [Wittgenstein] |
18728 | The meaning of a proposition is the mode of its verification [Wittgenstein] |
18705 | Words function only in propositions, like levers in a machine [Wittgenstein] |
18711 | A proposition is any expression which can be significantly negated [Wittgenstein] |
18733 | Laws of nature are an aspect of the phenomena, and are just our mode of description [Wittgenstein] |