8 ideas
| 2945 | Most philosophers start with reality and then examine knowledge; Descartes put the study of knowledge first [Lehrer] |
| Full Idea: Some philosophers (e.g Plato) begin with an account of reality, and then appended an account of how we can know it, ..but Descartes turned the tables, insisting that we must first decide what we can know. | |
| From: Keith Lehrer (Theory of Knowledge (2nd edn) [2000], I p.2) |
| 2946 | You cannot demand an analysis of a concept without knowing the purpose of the analysis [Lehrer] |
| Full Idea: An analysis is always relative to some objective. It makes no sense to simply demand an analysis of goodness, knowledge, beauty or truth, without some indication of the purpose of the analysis. | |
| From: Keith Lehrer (Theory of Knowledge (2nd edn) [2000], I p.7) | |
| A reaction: Your dismantling of a car will go better if you know what a car is for, but you can still take it apart in ignorance. |
| 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 |
| 3286 | An organism is conscious if and only if there is something it is like to be that organism [Nagel] |
| Full Idea: An organism only has conscious mental states if and only if there is something that it is like to be that organism. | |
| From: Thomas Nagel (What is it like to be a bat? [1974], p.166) | |
| A reaction: It is hard to argue with this, but one should push on and ask what features of its consciousness make it such that there is a 'what it is like'. What is it like to have a subconscious mind, or be deeply asleep, or drive while daydreaming? |
| 3288 | Can we describe our experiences to zombies? [Nagel] |
| Full Idea: The goal of an objective phenomenology would be to describe, at least in part, the subjective character of experiences in a form comprehensible to beings incapable of having those experiences. | |
| From: Thomas Nagel (What is it like to be a bat? [1974], p.179) | |
| A reaction: This seems a bizarre expectation. We can already explain visual experience to the blind up to a point, but no one is dreaming of an "objective phenomenology" which will give blind people total understanding, just by reading about it in braille. |
| 4883 | Nagel's title creates an impenetrable mystery, by ignoring a bat's ways that may not be "like" anything [Dennett on Nagel] |
| Full Idea: Nagel's title invites us to ignore all the different ways in which bats might accomplish their cunning feats without its "being like" anything for them. We create an impenetrable mystery for ourselves if we assume that Nagel's title makes sense. | |
| From: comment on Thomas Nagel (What is it like to be a bat? [1974]) by Daniel C. Dennett - Kinds of Minds Ch.6 | |
| A reaction: This could well be correct about bats, but the question applies to humans as well, and we can't deny that "what it is like" is a feature of some creatures' realities. On the fringes of our own consciousness there are mental events that are "like" nothing. |
| 3287 | We can't be objective about experience [Nagel] |
| Full Idea: If the subjective character of experience is fully comprehensible only from one point of view, then any shift to greater objectivity does not take us nearer to the real nature of the phenomenon: it takes us further away from it. | |
| From: Thomas Nagel (What is it like to be a bat? [1974], p.174) | |
| A reaction: We can, however, talk to one another about our subjectivity, and compare notes, and such 'inter-subjectivity' may be one approach to objectivity. We must concede Nagel's point, but we also miss something about a stone if we must remain outside of it. |
| 4989 | Physicalism should explain how subjective experience is possible, but not 'what it is like' [Kirk,R on Nagel] |
| Full Idea: A physicalist account of conscious experience must explain how it is possible for a physical system to be a conscious subject, but not 'what it is like' for some organism. | |
| From: comment on Thomas Nagel (What is it like to be a bat? [1974]) by Robert Kirk - Mind and Body §4.2 | |
| A reaction: You can't entirely evade Nagel's challenge. We are trying to discover the 'neural correlate of consciousness', which will explain why we are conscious, but we also want to know why we experience green for one wavelength, and red for another. |