14 ideas
| 2546 | Philosophy is a magnificent failure in its attempt to overstep the limits of our knowledge [McGinn] |
| Full Idea: Philosophy marks the limits of human theoretical intelligence. Philosophy is an attempt to overstep our cognitive bounds, a kind of magnificent failure. | |
| From: Colin McGinn (The Mysterious Flame [1999], p.209) | |
| A reaction: No one attempts to overstep boundaries once they are confirmed as such. The magnificent attempts persist because failure is impossible to demonstrate (except, perhaps, by Gödel's Theorem). |
| 11022 | Gentzen introduced a natural deduction calculus (NK) in 1934 [Gentzen, by Read] |
| Full Idea: Gentzen introduced a natural deduction calculus (NK) in 1934. | |
| From: report of Gerhard Gentzen (works [1938]) by Stephen Read - Thinking About Logic Ch.8 |
| 2544 | Thoughts have a dual aspect: as they seem to introspection, and their underlying logical reality [McGinn] |
| Full Idea: Our thoughts have a kind of duality, corresponding to their surface appearance to introspection and their underlying logical reality. | |
| From: Colin McGinn (The Mysterious Flame [1999], p.147) |
| 11065 | The inferential role of a logical constant constitutes its meaning [Gentzen, by Hanna] |
| Full Idea: Gentzen argued that the inferential role of a logical constant constitutes its meaning. | |
| From: report of Gerhard Gentzen (works [1938]) by Robert Hanna - Rationality and Logic 5.3 | |
| A reaction: Possibly inspired by Wittgenstein's theory of meaning as use? This idea was the target of Prior's famous connective 'tonk', which has the role of implying anything you like, proving sentences which are not logical consequences. |
| 11023 | The logical connectives are 'defined' by their introduction rules [Gentzen] |
| Full Idea: The introduction rules represent, as it were, the 'definitions' of the symbols concerned, and the elimination rules are no more, in the final analysis, than the consequences of these definitions. | |
| From: Gerhard Gentzen (works [1938]), quoted by Stephen Read - Thinking About Logic Ch.8 | |
| A reaction: If an introduction-rule (or a truth table) were taken as fixed and beyond dispute, then it would have the status of a definition, since there would be nothing else to appeal to. So is there anything else to appeal to here? |
| 11213 | Each logical symbol has an 'introduction' rule to define it, and hence an 'elimination' rule [Gentzen] |
| Full Idea: To every logical symbol there belongs precisely one inference figure which 'introduces' the symbol ..and one which 'eliminates' it. The introductions represent the 'definitions' of the symbols concerned, and eliminations are consequences of these. | |
| From: Gerhard Gentzen (works [1938], II.5.13), quoted by Ian Rumfitt - "Yes" and "No" III | |
| A reaction: [1935 paper] This passage is famous, in laying down the basics of natural deduction systems of logic (ones using only rules, and avoiding axioms). Rumfitt questions whether Gentzen's account gives the sense of the connectives. |
| 10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
| Full Idea: Gentzen proved the consistency of arithmetic from assumptions which transcend arithmetic. | |
| From: report of Gerhard Gentzen (works [1938]) by Alan Musgrave - Logicism Revisited §5 | |
| A reaction: This does not contradict Gödel's famous result, but reinforces it. The interesting question is what assumptions Gentzen felt he had to make. |
| 2539 | Mental modules for language, social, action, theory, space, emotion [McGinn] |
| Full Idea: The prevailing view in cognitive psychology is that the mind consists of separate faculties, each with a certain cognitive task: linguistic, social, practical, theoretical, abstract, spatial and emotional. | |
| From: Colin McGinn (The Mysterious Flame [1999], p.40) | |
| A reaction: 'Faculties' are not quite the same as 'modules', and this list mostly involves more higher-order activities than a modules list (e.g. Idea 2495). The idea that emotion is a 'faculty' sounds old-fashioned. |
| 2545 | Free will is mental causation in action [McGinn] |
| Full Idea: Free will is mental causation in action. | |
| From: Colin McGinn (The Mysterious Flame [1999], p.167) |
| 2543 | Brains aren't made of anything special, suggesting panpsychism [McGinn] |
| Full Idea: All matter must contain the potential to underlie consciousness, since there is nothing special about the matter that composes brain tissue. | |
| From: Colin McGinn (The Mysterious Flame [1999], p.100) | |
| A reaction: This seems to me one of the most basic assumptions which we should all make about the mind. The mind is made of the brain, and the brain is made of food. However, there must be something 'special' about the brain. |
| 2540 | Examining mind sees no brain; examining brain sees no mind [McGinn] |
| Full Idea: You can look into your mind until you burst and not discover neurons and synapses, and you can stare at someone's brain from dawn till dusk and not perceive the consciousness that is so apparent to the person whose brain it is. | |
| From: Colin McGinn (The Mysterious Flame [1999], p.47) | |
| A reaction: This is a striking symmetry of ignorance, though hardly enough to justify McGinn's pessimism about understanding the mind. 'When you are in the grass you can't see the whole of England; if you can see the whole of England, you won't see the grass'. |
| 2547 | There is information if there are symbols which refer, and which can combine into a truth or falsehood [McGinn] |
| Full Idea: There is information in a system if there are symbols in it that refer to things and that together form strings that can be true or false. | |
| From: Colin McGinn (The Mysterious Flame [1999], p.225) | |
| A reaction: We can also directly apprehend information by perception. Are facts identical with correct information? Can a universal generalisation be information? |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
| 2542 | Causation in the material world is energy-transfer, of motion, electricity or gravity [McGinn] |
| Full Idea: Causation in the material world works by energy transfer of some sort: transfer of motion, of electrical energy, of gravitational force. | |
| From: Colin McGinn (The Mysterious Flame [1999], p.92) |