13. Whether in change of thinking substances there can be one person.
But next, as to the first part of the question,
Whether, if the same thinking substance (supposing immaterial substances only to think) be changed, it can be the
same person? I answer, that cannot be resolved but by those who know what kind of substances they are that do
think; and whether the consciousness of past actions can be transferred from one thinking substance to another. I
grant were the same consciousness the same individual action it could not: but it being a present representation of
a past action, why it may not be possible, that that may be represented to the mind to have been which really never
was, will remain to be shown. And therefore how far the consciousness of past actions is annexed to any
individual agent, so that another cannot possibly have it, will be hard for us to determine, till we know what kind
of action it is that cannot be done without a reflex act of perception accompanying it, and how performed by
thinking substances, who cannot think without being conscious of it. But that which we call the same
consciousness, not being the same individual act, why one intellectual substance may not have represented to it, as
done by itself, what it never did, and was perhaps done by some other agent--why, I say, such a representation
may not possibly be without reality of matter of fact, as well as several representations in dreams are, which yet
whilst dreaming we take for true--will be difficult to conclude from the nature of things. And that it never is so,
will by us, till we have clearer views of the nature of thinking substances, be best resolved into the goodness of
God; who, as far as the happiness or misery of any of his sensible creatures is concerned in it, will not, by a fatal
error of theirs, transfer from one to another that consciousness which draws reward or punishment with it. How
far this may be an argument against those who would place thinking in a system of fleeting animal spirits, I leave
to be considered. But yet, to return to the question before us, it must be allowed, that, if the same consciousness
(which, as has been shown, is quite a different thing from the same numerical figure or motion in body) can be
transferred from one thinking substance to another, it will be possible that two thinking substances may make but
one person. For the same consciousness being preserved, whether in the same or different substances, the personal
identity is preserved.