Similarly, in the case of remembrance, he who remembers being also the one who saw, the two are identical. Thus only can a person, after shutting his eyes, remember the forms he has seen before, just as he saw them. Therefore that is is shut is not the seer; but that which, when the eyes are shut, sees forms in remembrance, must have been the seer when the eyes were open. This is further proved by the fact that when the body is dead, no vision takes place although the body is intact. If the body itself were the seer, even a dead body would continue to see and do similar functions. Therefore it is clear that the real agent of seeing etc. is not the body, but that whose absence deprives the body of the power of vision, and whose presence gives it that power.Brh.Up. IV.iii.6
Objection: Suppose the eyes and other organs themselves were the agents of vision and so forth
Reply: No: the remembrance that one is touching the very thing that one has seen, would be impossible is there were different agents for these two acts
Objection: Then let us say, it is the mind.
Reply: No, the mind also, being an object like colour etc cannot be the agent of vision and so forth. Therefore we conclude that the light in question is inside the body, and yet different from it like the sun etc.
That Similarly in the case of remembrance, he who remembers being also the one who saw, the two are identical. is the answer to ‘how do you know’ you are the same. No empiricist thinks that ‘I just know’ is an answer because it is a fundamental stance that a demand for a reason must be met with evidence of some sort. I know I was the one who found the wallet because I remember the wallet being found and oh yes i remember it was me that found it. Such an account is not convincing in the least. In fact no one offers a reason because they don’t need one. They may feel that they could but when they try they fail.
The remark about a dead body not being aware is based on the assumption that the life force which is identified with consciousness and the self is not present. A body on its own is not sufficient for awareness. This may seem obvious and hardly an argument but the point is that like in the case of remembrance being a remembrance no argument is required. We just know that a dead body is a dead body.
Is this armchair philosophy or fatuous maundering compared to neuroscience? I think of it as ‘asana’ philosophy after the meditation sitting position. There is no grasping of the self because there is no need. Neuroscience tries to offer evidence for our self-identity but none is required. Any mental state whatever is saturated in self-identity.