3

the subject of careful discussion between my
father and me at the time he had his defi-
nition under consideration. But first I had
better notice an objection which will seem weighty
to superficial minds. Namely, it will be said
that much necessary reasoning is not at all
mathematical. On that I take direct issue. Emi-
nent jurists, moralists, and philosophers can be found whose
powers of reasoning are famous,
and who yet declare that they have no
head for mathematics. This is, in part, a delusion
owing to bad instruction which has given rise to such
an aversion to everything that seems mathematical
that as soon as once talks to them of x, y, z, they
stop thinking. But what is also true of these persons