3 ideas
8754 | Logic is dependent on mathematics, not the other way round [Heyting, by Shapiro] |
Full Idea: Heyting (the intuitionist pupil of Brouwer) said that 'logic is dependent on mathematics', not the other way round. | |
From: report of Arend Heyting (Intuitionism: an Introduction [1956]) by Stewart Shapiro - Thinking About Mathematics 7.3 | |
A reaction: To me, this claim makes logicism sound much more plausible, as I don't see how mathematics could get beyond basic counting without a capacity for logical thought. Logic runs much deeper, psychologically and metaphysically. |
19393 | What is not active is nothing [Leibniz] |
Full Idea: We can now show from the inner truths of metaphysics that what is not active is nothing. | |
From: Gottfried Leibniz (True Method in Philosophy and Theology [1686], p.64) | |
A reaction: This is Leibniz's rebellion against the Cartesian idea that all that matters for natural existence is spatial extension. I agree (tentatively) with Leibniz's vision of nature here. Modern physics reveals a seething turmoil beneath the placid exterior. |
12582 | The function of beliefs is to produce beliefs-that-p when p [Millikan] |
Full Idea: Presumably it is a proper function of the belief-manufacturing mechanisms in John to produce beliefs-that-p only if and when p. | |
From: Ruth Garrett Millikan (Thoughts without Laws [1986], p.69), quoted by Christopher Peacocke - A Study of Concepts 5.2 | |
A reaction: This is the 'teleological' account of belief, which is trying to fit belief into an evolutionary view of humans. It is doubtful whether you can say mental states are just their 'proper' function, because then piano-playing becomes a puzzle. |