29 ideas
| 21544 | It seems that when a proposition is false, something must fail to subsist [Russell] |
| Full Idea: It seems that when a proposition is false, something does not subsist which would subsist if the proposition were true. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.76) | |
| A reaction: This looks to me like a commitment by Russell to the truthmaker principle. The negations of false propositions are made true by some failure of existence in the world. |
| 21539 | Excluded middle can be stated psychologically, as denial of p implies assertion of not-p [Russell] |
| Full Idea: The law of excluded middle may be stated in the form: If p is denied, not-p must be asserted; this form is too psychological to be ultimate, but the point is that it is significant and not a mere tautology. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.41) | |
| A reaction: 'Psychology' is, of course, taboo, post-Frege, though I think it is interesting. Stated in this form the law looks more false than usual. I can be quite clear than p is unacceptable, but unclear about its contrary. |
| 12456 | I aim to establish certainty for mathematical methods [Hilbert] |
| Full Idea: The goal of my theory is to establish once and for all the certitude of mathematical methods. | |
| From: David Hilbert (On the Infinite [1925], p.184) | |
| A reaction: This is the clearest statement of the famous Hilbert Programme, which is said to have been brought to an abrupt end by Gödel's Incompleteness Theorems. |
| 12461 | We believe all mathematical problems are solvable [Hilbert] |
| Full Idea: The thesis that every mathematical problem is solvable - we are all convinced that it really is so. | |
| From: David Hilbert (On the Infinite [1925], p.200) | |
| A reaction: This will include, for example, Goldbach's Conjecture (every even is the sum of two primes), which is utterly simple but with no proof anywhere in sight. |
| 9633 | No one shall drive us out of the paradise the Cantor has created for us [Hilbert] |
| Full Idea: No one shall drive us out of the paradise the Cantor has created for us. | |
| From: David Hilbert (On the Infinite [1925], p.191), quoted by James Robert Brown - Philosophy of Mathematics | |
| A reaction: This is Hilbert's famous refusal to accept any account of mathematics, such as Kant's, which excludes actual infinities. Cantor had laid out a whole glorious hierarchy of different infinities. |
| 12460 | We extend finite statements with ideal ones, in order to preserve our logic [Hilbert] |
| Full Idea: To preserve the simple formal rules of ordinary Aristotelian logic, we must supplement the finitary statements with ideal statements. | |
| From: David Hilbert (On the Infinite [1925], p.195) | |
| A reaction: I find very appealing the picture of mathematics as rooted in the physical world, and then gradually extended by a series of 'idealisations', which should perhaps be thought of as fictions. |
| 12462 | Only the finite can bring certainty to the infinite [Hilbert] |
| Full Idea: Operating with the infinite can be made certain only by the finitary. | |
| From: David Hilbert (On the Infinite [1925], p.201) | |
| A reaction: See 'Compactness' for one aspect of this claim. I think Hilbert was fighting a rearguard action, and his idea now has few followers. |
| 12455 | The idea of an infinite totality is an illusion [Hilbert] |
| Full Idea: Just as in the limit processes of the infinitesimal calculus, the infinitely large and small proved to be a mere figure of speech, so too we must realise that the infinite in the sense of an infinite totality, used in deductive methods, is an illusion. | |
| From: David Hilbert (On the Infinite [1925], p.184) | |
| A reaction: This is a very authoritative rearguard action. I no longer think the dispute matters much, it being just a dispute over a proposed new meaning for the word 'number'. |
| 12457 | There is no continuum in reality to realise the infinitely small [Hilbert] |
| Full Idea: A homogeneous continuum which admits of the sort of divisibility needed to realise the infinitely small is nowhere to be found in reality. | |
| From: David Hilbert (On the Infinite [1925], p.186) | |
| A reaction: He makes this remark as a response to Planck's new quantum theory (the year before the big works of Heisenberg and Schrödinger). Personally I don't see why infinities should depend on the physical world, since they are imaginary. |
| 12459 | The subject matter of mathematics is immediate and clear concrete symbols [Hilbert] |
| Full Idea: The subject matter of mathematics is the concrete symbols themselves whose structure is immediately clear and recognisable. | |
| From: David Hilbert (On the Infinite [1925], p.192) | |
| A reaction: I don't think many people will agree with Hilbert here. Does he mean token-symbols or type-symbols? You can do maths in your head, or with different symbols. If type-symbols, you have to explain what a type is. |
| 18112 | Mathematics divides in two: meaningful finitary statements, and empty idealised statements [Hilbert] |
| Full Idea: We can conceive mathematics to be a stock of two kinds of formulas: first, those to which the meaningful communications of finitary statements correspond; and secondly, other formulas which signify nothing and which are ideal structures of our theory. | |
| From: David Hilbert (On the Infinite [1925], p.196), quoted by David Bostock - Philosophy of Mathematics 6.1 |
| 21538 | If two people perceive the same object, the object of perception can't be in the mind [Russell] |
| Full Idea: If two people can perceive the same object, as the possibility of any common world requires, then the object of an external perception is not in the mind of the percipient. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.33) | |
| A reaction: This is merely an assertion of the realist view, rather than an argument. I take representative realism to tell a perfectly good story that permits two subjective representations of the same object. |
| 21534 | The only thing we can say about relations is that they relate [Russell] |
| Full Idea: It may be doubted whether relations can be adequately characterised by anything except the fact that they relate. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.27) | |
| A reaction: We can characterise a rope that ties things together. If I say 'stand to his left', do I assume the existence of one of the relata and the relation, but without the second relata? How about 'you two stand over there, with him on the left'? |
| 21540 | Relational propositions seem to be 'about' their terms, rather than about the relation [Russell] |
| Full Idea: In some sense which it would be very desirable to define, a relational proposition seems to be 'about' its terms, in a way in which it is not about the relation. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.53) | |
| A reaction: Identifying how best to specify what a proposition is actually 'about' is a very illuminating mode of enquiry. You can't define 'underneath' without invoking a pair of objects to illustrate it. A proposition can still focus on the relation. |
| 21536 | When I perceive a melody, I do not perceive the notes as existing [Russell] |
| Full Idea: When, after hearing the notes of a melody, I perceive the melody, the notes are not presented as still existing. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.31) | |
| A reaction: This is a good example, supporting Meinong's idea that we focus on 'intentional objects', rather than actual objects. |
| 21535 | Objects only exist if they 'occupy' space and time [Russell] |
| Full Idea: Only those objects exist which have to particular parts of space and time the special relation of 'occupying' them. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.29) | |
| A reaction: He excepts space and time themselves. Clearly this doesn't advance our understanding much, but it points to a priority in our normal conceptual scheme. Is Russell assuming absolute space and time? |
| 15959 | If the substantial form of brass implies its stability, how can it melt and remain brass? [Alexander,P] |
| Full Idea: If we account for the stability of a piece of brass by reference to the substantial form of brass, then it is mysterious how it can be melted and yet remain brass. | |
| From: Peter Alexander (Ideas, Qualities and Corpuscles [1985], 02.3) | |
| A reaction: [Alexander is discussing Boyle] |
| 15956 | The peripatetics treated forms and real qualities as independent of matter, and non-material [Alexander,P] |
| Full Idea: The peripatetic philosophers, in spite of their disagreements, all treated forms and real qualities as independent of matter and not to be understood in material terms. | |
| From: Peter Alexander (Ideas, Qualities and Corpuscles [1985], 54) | |
| A reaction: This is the simple reason why hylomorphism became totally discredited, in the face of the 'mechanical philosophy'. But there must be a physical version of hylomorphism, and I don't think Aristotle himself would reject it. |
| 21533 | Contingency arises from tensed verbs changing the propositions to which they refer [Russell] |
| Full Idea: Contingency derives from the fact that a sentence containing a verb in the present tense - or sometimes in the past or the future - changes its meaning continually as the present changes, and stands for different propositions at different times. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.26) | |
| A reaction: This immediately strikes me as a bad example of the linguistic approach to philosophy. As if we (like any animal) didn't have an apprehension prior to any language that most parts of experience are capable of change. |
| 9636 | My theory aims at the certitude of mathematical methods [Hilbert] |
| Full Idea: The goal of my theory is to establish once and for all the certitude of mathematical methods. | |
| From: David Hilbert (On the Infinite [1925], p.184), quoted by James Robert Brown - Philosophy of Mathematics Ch.5 | |
| A reaction: This dream is famous for being shattered by Gödel's Incompleteness Theorem a mere six years later. Neverless there seem to be more limited certainties which are accepted in mathematics. The certainty of the whole of arithmetic is beyond us. |
| 21537 | I assume we perceive the actual objects, and not their 'presentations' [Russell] |
| Full Idea: I prefer to advocate ...that the object of a presentation is the actual external object itself, and not any part of the presentation at all. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.33) | |
| A reaction: Although I am a fan of the robust realism usually favoured by Russell, I think he is wrong. I take Russell to be frightened that once you take perception to be of 'presentations' rather than things, there is a slippery slope to anti-realism. Not so. |
| 21532 | Full empiricism is not tenable, but empirical investigation is always essential [Russell] |
| Full Idea: Although empiricism as a philosophy does not appear to be tenable, there is an empirical manner of investigating, which should be applied in every subject-matter | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.22) | |
| A reaction: Given that early Russell loads his ontology with properties and propositions, this should come as no surprise, even if J.S. Mill was his godfather. |
| 15975 | Can the qualities of a body be split into two groups, where the smaller explains the larger? [Alexander,P] |
| Full Idea: Is there any way of separating the qualities that bodies appear to have into two groups, one as small as possible and the other as large as possible, such that the smaller group can plausibly be used to explain the larger? | |
| From: Peter Alexander (Ideas, Qualities and Corpuscles [1985], 5.02) | |
| A reaction: Alexander implies that this is a question Locke asked himself. This is pretty close to what I take to be the main question for essentialism, though I am cautious about couching it in terms of groups of qualities. I think this was Aristotle's question. |
| 21542 | Do incorrect judgements have non-existent, or mental, or external objects? [Russell] |
| Full Idea: Correct judgements have a transcendent object; but with regard to incorrect judgements, it remains to examine whether 1) the object is immanent, 2) there is no object, or 3) the object is transcendent. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.67) | |
| A reaction: Why is it that only Russell seems to have taken this problem seriously? Its solution gives the clearest possible indicator of how the mind relates to the world. |
| 21541 | The complexity of the content correlates with the complexity of the object [Russell] |
| Full Idea: Every property of the object seems to demand a strictly correlative property of the content, and the content, therefore, must have every complexity belonging to the object. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.55) | |
| A reaction: This claim gives a basis for his 'congruence' account of the correspondence theory of truth. It strikes me as false. If I talk of the 'red red robin', I don't mention the robin's feet. He ignores the psychological selection we make in abstraction. |
| 21543 | If p is false, then believing not-p is knowing a truth, so negative propositions must exist [Russell] |
| Full Idea: If p is a false affirmative proposition ...then it seems obvious that if we believe not-p we do know something true, so belief in not-p must be something which is not mere disbelief. This proves that there are negative propositions. | |
| From: Bertrand Russell (Meinong on Complexes and Assumptions [1904], p.75) | |
| A reaction: This evidently assumes excluded middle, but is none the worse for that. But it sounds suspiciously like believing there is no rhinoceros in the room. Does such a belief require a fact? |
| 15963 | Science has been partly motivated by the belief that the universe is run by God's laws [Alexander,P] |
| Full Idea: The idea of a designed universe has not been utterly irrelevant to the scientific project; it is one of the beliefs that can give a scientist the faith that there are laws, waiting to be discovered, that govern all phenomena. | |
| From: Peter Alexander (Ideas, Qualities and Corpuscles [1985], 03.3) | |
| A reaction: Of course if you start out looking for the 'laws of God' that is probably what you will discover. Natural selection strikes me as significant, because it shows no sign of being a procedure appropriate to a benevolent god. |
| 15951 | Alchemists tried to separate out essences, which influenced later chemistry [Alexander,P] |
| Full Idea: The alchemists sought the separation of the 'pure essences' of substances from unwanted impurities. This last goal was of great importance for the development of modern chemistry at the hands of Boyle and his successors. | |
| From: Peter Alexander (Ideas, Qualities and Corpuscles [1985], 01.1) | |
| A reaction: In a nutshell this gives us the reason why essences are so important, and also why they became discredited. Time for a clear modern rethink. |
| 15981 | Absolute space either provides locations, or exists but lacks 'marks' for locations [Alexander,P] |
| Full Idea: There are two conceptions of absolute space. In the first, empty space is independent of objects but provides a frame of reference so an object has a location. ..In the second space exists independently, but has no 'marks' into which objects can be put. | |
| From: Peter Alexander (Ideas, Qualities and Corpuscles [1985], 6) | |
| A reaction: He says that Locke seems to reject the first one, but accept the second one. |