22 ideas
13917 | Metaphysics aims to identify categories of being, and show their interdependency [Lowe] |
13919 | Philosophy aims not at the 'analysis of concepts', but at understanding the essences of things [Lowe] |
18951 | For scientific purposes there is a precise concept of 'true-in-L', using set theory [Putnam] |
18953 | Modern notation frees us from Aristotle's restriction of only using two class-names in premises [Putnam] |
18949 | The universal syllogism is now expressed as the transitivity of subclasses [Putnam] |
18952 | '⊃' ('if...then') is used with the definition 'Px ⊃ Qx' is short for '¬(Px & ¬Qx)' [Putnam] |
18958 | In type theory, 'x ∈ y' is well defined only if x and y are of the appropriate type [Putnam] |
18954 | Before the late 19th century logic was trivialised by not dealing with relations [Putnam] |
18956 | Asserting first-order validity implicitly involves second-order reference to classes [Putnam] |
18962 | Unfashionably, I think logic has an empirical foundation [Putnam] |
18961 | We can identify functions with certain sets - or identify sets with certain functions [Putnam] |
18955 | Having a valid form doesn't ensure truth, as it may be meaningless [Putnam] |
18959 | Sets larger than the continuum should be studied in an 'if-then' spirit [Putnam] |
18957 | Nominalism only makes sense if it is materialist [Putnam] |
18950 | Physics is full of non-physical entities, such as space-vectors [Putnam] |
13918 | Holes, shadows and spots of light can coincide without being identical [Lowe] |
13921 | All things must have an essence (a 'what it is'), or we would be unable to think about them [Lowe] |
13922 | Knowing an essence is just knowing what the thing is, not knowing some further thing [Lowe] |
13920 | Each thing has to be of a general kind, because it belongs to some category [Lowe] |
18960 | Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam] |
22381 | Being a good father seems to depend on intentions, rather than actual abilities [Foot] |
22380 | Some words, such as 'knife', have a meaning which involves its function [Foot] |