a different thing by the word same. We mean
indistinguishability. We mean that we cannot distinguish between the two
colours, the two notes, the two sensations. And this no doubt is a
relative knowledge, not a knowledge of things in themselves. But we do
not mean incapacity of being distinguished when we speak of our own
personal identity. When a man thinks to-day of his life of yesterday,
and regards himself as the same being through, all the time, he does
not simply mean that he cannot distinguish between the being that
existed yesterday according to his memory and the being that exists
to-day according to his present consciousness: he means that the being
is one and the same absolutely and in itself.

And this conviction of personal identity will presently be found to fall
in with the revelation of the Moral Law, which is my subject in this
Lecture. For it is by virtue of this personal identity that I become
responsible for my actions. I am not merely the same thinking subject, I
am the same moral agent all through my life. If I changed as fast as the
phenomena of my being changed, my responsibility for any evil deed would
cease the moment the deed was done. No punishment would be just, because
it would not be just to punish one being for the faults of a totally
different being. The Moral Law in its application to man requires as a
basis the personal identity of each man with himself.

If corroboration were needed of the directness of the intuition by which
we get this idea of our own personal identity, it would be found in the
entire failure of all attempts to derive that idea from any other
source. Comte, the founder of the Positive School, can do nothing with
this idea but suggest that it is probably the result of some obscure
synergy or co-operation of the faculties. John Stuart Mill passes it by
altogether as lying outside the scope of his enquiries and of his
doctrine. Mr. Herbert Spencer deals with it in a very weak chapter[1] of
his remarkable volume of First Principles. He divides all the
manifestations made to our consciousness, or, as we commonly say, all
our sensations, into two great classes. He selects as the main but not
universal characteristic of the one class, vividness; of the other
class, faintness; a distinction first insisted on, though somewhat
differently applied, by Hume. He adds various other characteristics of
each class, some of them implying very questionable propositions. And we
come fi