Full Idea
If any man shall take the words number and sum in a larger sense, to understand things which are numberless and sumless (such as the infinite points on a line), I could allow him the contradictious phrase 'innumerable number' without absurdity.
Gist of Idea
We can talk of 'innumerable number', about the infinite points on a line
Source
Isaac Newton (Letters to Bentley [1692], 1693.02.25)
Book Reference
Newton,Isaac: 'Philosophical Writings' [CUP 2004], p.103
A Reaction
[compressed] I take the key point here to be the phrase of taking number 'in a larger sense'. Like the word 'atom' in physics, the word 'number' retains its traditional reference, but has considerably shifted its scope. Amateurs must live with this.