13 ideas
13832 | Natural deduction shows the heart of reasoning (and sequent calculus is just a tool) [Gentzen, by Hacking] |
Full Idea: Gentzen thought that his natural deduction gets at the heart of logical reasoning, and used the sequent calculus only as a convenient tool for proving his chief results. | |
From: report of Gerhard Gentzen (Investigations into Logical Deduction [1935]) by Ian Hacking - What is Logic? §05 |
20189 | Belief is a feeling, independent of the will, which arises from uncontrolled and unknown causes [Hume] |
Full Idea: Belief consists merely in a certain feeling or sentiment; in something, that depends not on the will, but must arise from certain determinate causes and principles, of which we are not master. | |
From: David Hume (Treatise of Human Nature, + Appendix [1740], Appen p.2) | |
A reaction: This is the opposite of Descartes' 'doxastic voluntarism' (i.e. we choose what to believe). If you want to become a Christian, steep yourself in religious literature, and the company of religious people. It will probably work. |
21309 | A proposition cannot be intelligible or consistent, if the perceptions are not so [Hume] |
Full Idea: No proposition can be intelligible or consistent with regard to objects, which is not so with regard to perceptions. | |
From: David Hume (Treatise of Human Nature, + Appendix [1740], Appendix) | |
A reaction: An interesting variant on expressions of the empiricist principle. Presumably one can say intelligible things about Escher drawings. |
15755 | Hume needs a notion which includes degrees of resemblance [Shoemaker on Hume] |
Full Idea: Hume needs a notion of resemblance where some things resemble a given thing more than other things do, and some may resemble exactly, and some hardly at all. | |
From: comment on David Hume (Treatise of Human Nature, + Appendix [1740]) by Sydney Shoemaker - Causality and Properties §02 | |
A reaction: An astute and simple point. Once you admit degrees of resemblance, of course, then resemblance probably ceases to be a primitive concept in your system, and Hume would be well stuck. |
5323 | Experiences are logically separate, but factually linked by simultaneity or a feeling of continuousness [Ayer on Hume] |
Full Idea: Our experiences are logically independent, but they may be factually connected. What unites them is that either they are experienced together, or (if at separate times) they are separated by a stream of experience which is felt to be continuous. | |
From: comment on David Hume (Treatise of Human Nature, + Appendix [1740], Bk 3 App.) by A.J. Ayer - The Central Questions of Philosophy §VI.A | |
A reaction: A strict empiricist cannot deny that the feeling of continuity could be false, though that invites the Cartesian question of what exactly is experiencing the delusion. Hume denies that we experience any link between simultaneous experiences. |
21311 | Are self and substance the same? Then how can self remain if substance changes? [Hume] |
Full Idea: Is the self the same with substance? If it be, how can that question have place concerning the subsistence of self, under a change of substance? If they be distinct, what is the difference between them? | |
From: David Hume (Treatise of Human Nature, + Appendix [1740], Appendix) | |
A reaction: Locke seems to think there is a characterless substance which supports momories, and the latter constitute the self. So if my substance acquires Nestor's memories, I become Nestor. Hume, the stricter empiricist, cares nothing for characterless things. |
21312 | Perceptions are distinct, so no connection between them can ever be discovered [Hume] |
Full Idea: If perceptions are distinct existences, they form a whole only by being connected together. But no connexions among distinct existences are ever discoverable. We only feel a connexion ...to pass from one object to another. | |
From: David Hume (Treatise of Human Nature, + Appendix [1740], Appendix) | |
A reaction: This first part of this is a problem for any 'bundle' theory of objects or self. This is why Hume abandons all hope for his theory of personal identity based on association. You infer the associations, but don't perceive them. |
21308 | We have no impression of the self, and we therefore have no idea of it [Hume] |
Full Idea: Every idea is derived from preceding impressions; and we have no impression of self or substance, as something simple and individual. We have, therefore, no idea of them in that sense. | |
From: David Hume (Treatise of Human Nature, + Appendix [1740], Appendix) | |
A reaction: This spells out with beautiful simplicity how his empiricist assumptions lead him to this sceptical view. No logical positivist could reject this thought. Personally I favour empiricism with added inference to the best explanation. |
21310 | Does an oyster with one perception have a self? Would lots of perceptions change that? [Hume] |
Full Idea: Suppose an oyster to have only one perception, as of thirst or hunger. Do you consider any thing but merely that perception? Have you any notion of self or substance? If not, the addition of other perceptions can never give you that notion. | |
From: David Hume (Treatise of Human Nature, + Appendix [1740], Appendix) | |
A reaction: A splendid addition to his earlier sceptical thinking. We could form a different conclusion. Suppose I do have a self. If my multitudinous perceptions were reduced to a single perception of agonising pain, would that remove the self? |
20074 | We can keep Davidson's account of intentions in action, by further explaining prior intentions [Davidson, by Stout,R] |
Full Idea: Davidson's original account of intentions might still stand if we could accept that prior intentions are different in kind from intentions with which one acts. | |
From: report of Donald Davidson (Problems in the Explanation of Action [1987]) by Rowland Stout - Action 8 'Davidson's' | |
A reaction: Davidson says prior intention is all-out judgement of desirability. Prior intentions are more deliberate, with the other intentions as a presumed background to action. Compare Sartre's dual account of the self. |
23115 | We have no natural love of mankind, other than through various relationships [Hume] |
Full Idea: It may be affirm'd, that there is no such passion in human minds, as the love of mankind, merely as such, independent of personal qualities, of services, or of relation to ourself. | |
From: David Hume (Treatise of Human Nature, + Appendix [1740], p.481), quoted by John Kekes - Against Liberalism 9.4 | |
A reaction: Hume says this is for the best. I can't imagine spontaneous love of human beings we have never met. It takes the teachings of some sort of doctrine - religious or political - to produce such an attitude. I see it as a distortion of love. A hijacking. |
16946 | Causation is just invariance, as long as it is described in general terms [Quine on Hume] |
Full Idea: Hume explained cause as invariable succession, and this makes sense as long as the cause and effect are referred to by general terms. … This account leaves singular causal statements unexplained. | |
From: comment on David Hume (Treatise of Human Nature, + Appendix [1740]) by Willard Quine - Natural Kinds p.131 | |
A reaction: A nice 20th century linguistic point made against a good 18th century theory. |
15250 | If impressions, memories and ideas only differ in vivacity, nothing says it is memory, or repetition [Whitehead on Hume] |
Full Idea: Hume confuses 'repetition of impressions' with 'impression of repetitions of impressions'. ...In order of 'force and vivacity' we have: impressions, memories, ideas. This omits the vital fact that memory is memory; the notion of repetition is lost. | |
From: comment on David Hume (Treatise of Human Nature, + Appendix [1740]) by Alfred North Whitehead - Process and Reality V.II | |
A reaction: [compressed; Harré and Madden spotted this idea] This seems to pinpoint rather nicely the hopeless thinness of Hume's account. He is so desperate to get it down to minimal empirical experience that his explanations are too thin. One big idea.... |