12 ideas
| 6021 | It is only when we say a proposition that we speak truly or falsely [Sext.Empiricus] |
| Full Idea: It is only when we say a proposition that we speak truly or falsely. | |
| From: Sextus Empiricus (Against the Professors (six books) [c.180], 8.74) | |
| A reaction: This makes assertions truth-bearers, rather than propositions. But a proposition can be true or false if it is stamped with a date and/or place. "Shakespeare was born in Stratford on 23rd April 1664". No one needs to assert that. |
| 6020 | 'Man is a rational mortal animal' is equivalent to 'if something is a man, that thing is a rational mortal animal' [Sext.Empiricus] |
| Full Idea: Definitions are identical to universal propositions in meaning, and only differ in syntax, for whoever says 'Man is a rational mortal animal' says the same thing in meaning as whoever says 'If something is a man, that thing is a rational mortal animal'. | |
| From: Sextus Empiricus (Against the Professors (six books) [c.180], 11.8) | |
| A reaction: How strikingly like Bertrand Russell's interest and solutions. Sextus shows a straightforward interest in logical form, of a kind we associate with the twentieth century. Did Sextus Empiricus invent quantification? |
| 9465 | Substitutional universal quantification retains truth for substitution of terms of the same type [Jacquette] |
| Full Idea: The substitutional interpretation says the universal quantifier is true just in case it remains true for all substitutions of terms of the same type as that of the universally bound variable. | |
| From: Dale Jacquette (Intro to III: Quantifiers [2002], p.143) | |
| A reaction: This doesn't seem to tell us how it gets started with being true. |
| 9466 | Nominalists like substitutional quantification to avoid the metaphysics of objects [Jacquette] |
| Full Idea: Some substitutional quantificationists in logic hope to avoid philosophical entanglements about the metaphysics of objects, ..and nominalists can find aid and comfort there. | |
| From: Dale Jacquette (Intro to III: Quantifiers [2002], p.143) | |
| A reaction: This has an appeal for me, particularly if it avoids abstract objects, but I don't see much problem with material objects, so we might as well have a view that admits those. |
| 6026 | How can you investigate without some preconception of your object? [Sext.Empiricus] |
| Full Idea: A preconception and conception must precede every object of investigation, for how can anyone even investigate without some conception of the object of investigation? | |
| From: Sextus Empiricus (Against the Professors (six books) [c.180], 8.331a) | |
| A reaction: The Duhem-Quine thesis about the 'theory-ladenness of observation' is just a revival of some routine ancient scepticism. As well as a conceptual scheme to accommodate the observation, there must also be some motivation for the investigation. |
| 7658 | Obviously there can't be a functional anaylsis of qualia if they are defined by intrinsic properties [Dennett] |
| Full Idea: If you define qualia as intrinsic properties of experiences considered in isolation from all their causes and effects, logically independent of all dispositional properties, then they are logically guaranteed to elude all broad functional analysis. | |
| From: Daniel C. Dennett (Sweet Dreams [2005], Ch.8) | |
| A reaction: This is a good point - it seems daft to reify qualia and imagine them dangling in mid-air with all their vibrant qualities - but that is a long way from saying there is nothing more to qualia than functional roles. Functions must be exlained too. |
| 7655 | The work done by the 'homunculus in the theatre' must be spread amongst non-conscious agencies [Dennett] |
| Full Idea: All the work done by the imagined homunculus in the Cartesian Theater must be distributed among various lesser agencies in the brain, none of which is conscious. | |
| From: Daniel C. Dennett (Sweet Dreams [2005], Ch.3) | |
| A reaction: Dennett's account crucially depends on consciousness being much more fragmentary than most philosophers claim it to be. It is actually full of joints, which can come apart. He may be right. |
| 7657 | Intelligent agents are composed of nested homunculi, of decreasing intelligence, ending in machines [Dennett] |
| Full Idea: As long as your homunculi are more stupid and ignorant than the intelligent agent they compose, the nesting of homunculi within homunculi can be finite, bottoming out, eventually, with agents so unimpressive they can be replaced by machines. | |
| From: Daniel C. Dennett (Sweet Dreams [2005], Ch.6) | |
| A reaction: [Dennett first proposed this in 'Brainstorms' 1978]. This view was developed well by Lycan. I rate it as one of the most illuminating ideas in the modern philosophy of mind. All complex systems (like aeroplanes) have this structure. |
| 7656 | I don't deny consciousness; it just isn't what people think it is [Dennett] |
| Full Idea: I don't maintain, of course, that human consciousness does not exist; I maintain that it is not what people often think it is. | |
| From: Daniel C. Dennett (Sweet Dreams [2005], Ch.3) | |
| A reaction: I consider Dennett to be as near as you can get to an eliminativist, but he is not stupid. As far as I can see, the modern philosopher's bogey-man, the true total eliminativist, simply doesn't exist. Eliminativists usually deny propositional attitudes. |
| 7654 | What matters about neuro-science is the discovery of the functional role of the chemistry [Dennett] |
| Full Idea: Neuro-science matters because - and only because - we have discovered that the many different neuromodulators and other chemical messengers that diffuse throughout the brain have functional roles that make important differences. | |
| From: Daniel C. Dennett (Sweet Dreams [2005], Ch.1) | |
| A reaction: I agree with Dennett that this is the true ground for pessimism about spectacular breakthroughs in artificial intelligence, rather than abstract concerns about irreducible features of the mind like 'qualia' and 'rationality'. |
| 6032 | Right actions, once done, are those with a reasonable justification [Sext.Empiricus] |
| Full Idea: Right action is whatever, once it has been done, has a reasonable justification. | |
| From: Sextus Empiricus (Against the Professors (six books) [c.180], 7.158) | |
| A reaction: Why does he add 'once it has been done'? Wouldn't a proposed action be right if it had a reasonable justification? This grows out of the classical and Stoic emphasis on reason in ethics, and leads towards Scanlon's Contractualism. |
| 1517 | The tektraktys (1+2+3+4=10) is the 'fount of ever-flowing nature' [Sext.Empiricus] |
| Full Idea: The tektraktys (1+2+3+4=10) is the 'fount of ever-flowing nature', because nature is a harmony of three concords (4th,5th and octave), and these ratios (4:3, 3:2, and 2:1) are found in the tektraktys. | |
| From: Sextus Empiricus (Against the Professors (six books) [c.180], 7.95) |