Full Idea
It is by the natural light that the axioms of mathematics are recognised. If we take away the same quantity from two equal things, …a thing we can easily predict without having experienced it.
Gist of Idea
We know mathematical axioms, such as subtracting equals from equals leaves equals, by a natural light
Source
Gottfried Leibniz (Letters to Queen Charlotte [1702], p.189)
Book Reference
Leibniz,Gottfried: 'Philosophical Essays', ed/tr. Arlew,R /Garber,D [Hackett 1989], p.189
A Reaction
He also says two equal weights will keep a balance level. Plato thinks his slave boy understands halving an area by the natural light, but that is just as likely to be experience. It is too easy to attribut thoughts to a 'natural light'.