147

Logic
147

a general idea of where I stand. I may, however say
that I am one of those who maintain that a proba-
bility must be a matter of positive knowledge, or confess
itself a nullity. Yet I do not go to such an extreme length
of empiricism as Mr. Venn. On the other hand, some
very acute, but in my opinion, quite untenable positions
of Mr. F. Y. Edgeworth will receive examination. It is
of the extremest importance to distinguish entirely
different quantities commonly confounded under the
name of probability. One of these, which I term "like-
believed" is the most deceptive thing in the world, being
nothing but the degree of conformity of a proposition to
our preconceived ideas. When this is dignified by the
name of probability, as if it were something on which
vast Insurance Companies could risk their hundreds
of millions, it does more harm than the yellow fever ever
did. The probability proper, as also an essentially inac-
urate idea, calling for every [??] of pragmatism