Hence, although Mill's definition of a proposition, given above, is adequate for propositions in general; yet that kind of proposition (the Real) with regard to which Logic (in Mill's view) investigates the conditions of proof, may be more explicitly and pertinently defined as 'a predication concerning the relation of matters of fact.' Sec.5.This leads to a very important distinction to which we shall often have to refer in subsequent pages--namely, the distinction between the Form and the Matter of a proposition or of an argument.

The distinction between Form and Matter, as it is ordinarily employed, is easily understood.

An apple growing in the orchard and a waxen apple on the table may have the same shape or form, but they consist of different materials; two real apples may have the same shape, but contain distinct ounces of apple-stuff, so that after one is eaten the other remains to be eaten.

Similarly, tables may have the same shape, though one be made of marble, another of oak, another of iron.

The form is common to several things, the matter is peculiar to each.