Single Idea 7700

[catalogued under 7. Existence / A. Nature of Existence / 4. Abstract Existence]

Full Idea

Let any man try to conceive a triangle in general, which is neither Isoceles nor Scalenum, nor has any particular length or proportion of sides; and he will perceive the absurdity of all the scholastic notions with regard to abstraction and general ideas.

Clarification

Isoceles and Scalene are particular shapes of triangle

Gist of Idea

We can't think about the abstract idea of triangles, but only of particular triangles

Source

David Hume (Enquiry Conc Human Understanding [1748], XII.II.122)

Book Reference

Hume,David: 'Enquiries Conc. Human Understanding, Morals', ed/tr. Selby-Bigge/Nidditch [OUP 1975], p.155


A Reaction

I think there is a basic error in this. I admit that I can only imagine a particular triangle, but it doesn't follow that I am thinking about one triangle. Ontology/epistemology confusion. I picture a shape while believing the shape to be irrelevant.