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Single Idea 9788

[filed under theme 18. Thought / E. Abstraction / 3. Abstracta by Ignoring ]

Full Idea

Mathematicians abstract properties which are conceptually separable from the world of change. It makes no difference if you treat them as separate, in the sense that it does not result in error.

Gist of Idea

Mathematicians study what is conceptually separable, and doesn't lead to error

Source

Aristotle (Physics [c.337 BCE], 193b33)

Book Ref

Aristotle: 'Physics', ed/tr. Waterfield,Robin [OUP 1996], p.36


A Reaction

This strikes me as a crucial point to make against Frege (if Aristotle is right). Frege hates abstractionism precisely because it is psychological, and hence admits subjective error, instead of objective truth. Does 'pure' abstraction avoid error?


The 23 ideas with the same theme [creating abstractions by ignoring some features]:

Mathematicians study quantity and continuity, and remove the perceptible features of things [Aristotle]
Mathematicians suppose inseparable aspects to be separable, and study them in isolation [Aristotle]
Mathematicians study what is conceptually separable, and doesn't lead to error [Aristotle]
Mathematical objects abstract both from perceived matter, and from particular substance [Aquinas]
We can just think of an apple's colour, because the apple is not part of the colour's nature [Aquinas]
Abstracting either treats something as separate, or thinks of it separately [Aquinas]
Numbers and shapes are abstracted by ignoring their sensible qualities [Aquinas]
Universals are just abstractions by concealing some of the circumstances [Leibniz]
Dedekind said numbers were abstracted from systems of objects, leaving only their position [Dedekind, by Dummett]
We derive the natural numbers, by neglecting everything of a system except distinctness and order [Dedekind]
The modern account of real numbers detaches a ratio from its geometrical origins [Frege]
Frege himself abstracts away from tone and color [Yablo on Frege]
If we abstract 'from' two cats, the units are not black or white, or cats [Tait on Frege]
Disregarding properties of two cats still leaves different objects, but what is now the difference? [Frege]
How do you find the right level of inattention; you eliminate too many or too few characteristics [Frege]
'Abstractionism' is acquiring a concept by picking out one experience amongst a group [Geach]
The Way of Abstraction says an incomplete description of a concrete entity is the complete abstraction [Lewis]
Maths deals with quantities of physical significance, ignoring irrelevant features [Geroch]
Abstractions come before the mind by concentrating on a part of what is presented [Campbell,K]
We can apprehend structures by focusing on or ignoring features of patterns [Shapiro]
We can focus on relations between objects (like baseballers), ignoring their other features [Shapiro]
A structure is an abstraction, focussing on relationships, and ignoring other features [Shapiro]
We can abstract to a dependent entity by blocking out features of its bearer [Koslicki]