6 ideas
| 9390 | Logic guides thinking, but it isn't a substitute for it [Rumfitt] |
| Full Idea: Logic is part of a normative theory of thinking, not a substitute for thinking. | |
| From: Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.13) | |
| A reaction: There is some sort of logicians' dream, going back to Leibniz, of a reasoning engine, which accepts propositions and outputs inferences. I agree with this idea. People who excel at logic are often, it seems to me, modest at philosophy. |
| 9389 | Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt] |
| Full Idea: Vagueness in respect of membership is consistency with determinacy of the set's identity, so long as a set's identity is taken to consist, not in its having such-and-such members, but in its being the extension of a concept. | |
| From: Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.5) | |
| A reaction: I find this view of sets much more appealing than the one that identifies a set with its members. The empty set is less of a problem, as well as non-existents. Logicians prefer the extensional view because it is tidy. |
| 7441 | Experiences are defined by their causal role, and causal roles belong to physical states [Lewis] |
| Full Idea: The definitive characteristic of any experience is its causal role, its most typical causes and effects; but we materialists believe that these causal roles which belong by analytic necessity to experiences belong in fact to certain physical states. | |
| From: David Lewis (An Argument for the Identity Theory [1966], §I) | |
| A reaction: This is the Causal version of functionalism, which Armstrong also developed. The word 'typical' leads later to a teleological element in the theory (e.g. in Lycan). There are other things to say about mental states than just their causal role. |
| 7442 | 'Pain' contingently names the state that occupies the causal role of pain [Lewis] |
| Full Idea: On my theory, 'pain' is a contingent name - that is, a name with different denotations in different possible worlds - since in any world, 'pain' names whatever state happens in that world to occupy the causal role definitive of pain. | |
| From: David Lewis (An Argument for the Identity Theory [1966], §II n6) | |
| A reaction: Better to say that 'pain' (like 'sound') is ambiguous. It is indiscriminately used by English-speakers to mean [1] the raw quale that we experience when damaged, and [2] whatever it is that leads to pain behaviour. Maybe frogs have 2 but not 1. |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| Full Idea: Archelaus was the first person to say that the universe is boundless. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
| Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
| A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |