Consciousness alone unites actions into the same Person.
 John Locke, An Essay Concerning Human Understanding (1689). copy citation

Context

“But yet, when we will inquire what makes the same SPIRIT, MAN, or PERSON, we must fix the ideas of spirit, man, or person in our minds; and having resolved with ourselves what we mean by them, it will not be hard to determine, in either of them, or the like, when it is the same, and when not. 18. Consciousness alone unites actions into the same Person. But though the same immaterial substance or soul does not alone, wherever it be, and in whatsoever state, make the same MAN; yet it is plain, consciousness, as far as ever it can be extended—should it be to ages past—unites existences and actions very remote in time into the same PERSON, as well as it does the existences and actions of the immediately preceding moment:” source