Concept
Extension (predicate logic)
Overview
The extension of a predicate – a truth-valued function – is the set of tuples of values that, used as arguments, satisfy the predicate. Such a set of tuples is a relation.
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
Possible passages
Found by search and not yet checked by a person; they may only mention the idea in passing.
They rightly think that only solid extension can make an impression on our senses. It thus seems to us that extension is an attribute which constitutes part of the metaphysical form, but we are far from thinking that extension constitutes its essence. However, before Descartes, some of the ancients made the essence of matter consist in solid extension. But this opinion, of which all the Cartesians have made much…
Julien Offray de La Mettrie, Man a Machine
The chapter “CHAPTER III. CONCERNING THE EXTENSION OF MATTER.” is titled for Extension; names Extension several times.
It is true, the idea of extension joins itself so inseparably with all visible, and most tangible qualities, that it suffers us to SEE no one, or FEEL very few external objects, without taking in impressions of extension too. This readiness of extension to make itself be taken notice of so constantly with other ideas, has been the occasion, I guess, that some have made the whole essence of body to consist in…
John Locke, An Essay Concerning Humane Understanding, Volume 1
Names Extension several times; states what Extension is.
For example, in milk there is an extension or diffusion of whiteness; in the diamond an extension or diffusion of hardness; in body in general a diffusion of antitypia or materiality. There is accordingly in body something anterior to extension."
John Dewey, Leibniz's New Essays Concerning the Human Understanding
Names Extension several times; states what Extension is.
Related ideas
Place in the tradition
Part of Outline of logic.
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