M.
Qu. whether the substance of body or anything else be [pg 020] any more than the collection of concrete ideas included in that thing? Thus the substance of any particular body is extension, solidity, figure[82]. Of general abstract body we can have no idea.
I.
Mem. Most carefully to inculcate and set forth that the endeavouring to express abstract philosophic thoughts by words unavoidably runs a man into difficulties. This to be done in the Introduction[83].
Mem. To endeavour most accurately to understand what is meant by this axiom: Quæ sibi mutuo congruunt æqualia sunt.
Qu. what the geometers mean by equality of lines, & whether, according to their definition of equality, a curve line can possibly be equal to a right line?
If wth me you call those lines equal wch contain an equal number of points, then there will be no difficulty. That curve is equal to a right line wch contains the same points as the right one doth.