We certainly cannot object that the subject of identity is not made plain. Who has explained identity, or motion, or cohesion, or crystallization, or any thing? Locke goes squarely at the subject of personal identity, (see Essay, ch. 27,) but has rendered us small aid. His definition is, “Existence itself, which determines a being of any sort, to a particular time and place, incommunicable to two beings of the same kind.” I had rather define it “the uninterrupted continuance of being.” What ceases to exist, cannot again exist: for then it would exist after it had ceased to exist, and would have existed before it existed. Locke makes _consciousness_ to constitute identity, and argues that a man and a person are not the same; and that hence if I kill a man, but was not conscious of what I did, or have utterly forgotten, I am not the same person. Watts shows up this notion of Locke very ludicrously. Butler, in his “Dissertation,” urges that consciousness _presupposes_ identity, as knowledge presupposes truth. On Locke’s theory, no person would have existed any earlier than the period to which his memory extends. We cannot suppose the soul made up of many consciousnesses, nor could memory, if material, spread itself over successive years of life.] [28] I say _kind_ of presumption or probability; for I do not mean to affirm that there is the same _degree_ of conviction, that our living powers will continue after death, as there is, that our substances will. [29] _Destruction of living powers_, is a manner of expression unavoidably ambiguous; and may signify either _the destruction of a living being, so as that the same living being shall be incapable of ever perceiving or acting again at all_; or _the destruction of those means and instruments by which it is capable of its present life, of its present state of perception and of action_. It is here used in the former sense. When it is used in the latter, the epithet _present_ is added. The loss of a man’s eye is a destruction of living powers in the latter sense. But we have no reason to think the destruction of living powers, in the former sense, to be possible. We have no more reason to think a being endued with living powers, ever loses them during its whole existence, than to believe that a stone ever acquires them. [30] [The next paragraph indicates that Butler does not, as Chalmers thinks, consider this argument as “handing us over to an absolute demonstration.” It just places all arguments for and against the soul’s future life, in that balanced condition, which leaves us to learn the fact from revelation, free from presumptions _against_ its truth. This view of the case entirely relieves the objection as to the future life of brutes; and shows how entirely we must rely on revelation, as to the future, both of man and beast.]