24 ideas
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] |
7548 | Classes, grouped by a convenient property, are logical constructions [Russell] |
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] |
7545 | Visible things are physical and external, but only exist when viewed [Russell] |
18957 | Nominalism only makes sense if it is materialist [Putnam] |
18950 | Physics is full of non-physical entities, such as space-vectors [Putnam] |
16776 | Substance is an intrinsic thing, so parts of substances can't also be intrinsic things [Duns Scotus] |
7549 | If my body literally lost its mind, the object seen when I see a flash would still exist [Russell] |
7553 | Sense-data are purely physical [Russell] |
18960 | Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam] |
7546 | A man is a succession of momentary men, bound by continuity and causation [Russell] |
7550 | We could probably, in principle, infer minds from brains, and brains from minds [Russell] |
7551 | Matter is a logical construction [Russell] |
7547 | Matter requires a division into time-corpuscles as well as space-corpuscles [Russell] |
7552 | Six dimensions are needed for a particular, three within its own space, and three to locate that space [Russell] |