24 R. Groan not, the human mind is immortal. A. How do you prove it? R. From those things which you have granted above, with great caution. A. I do not indeed recall to mind any want of vigilance in my admissions when questioned by you: but now gather all into one sum, I pray you; let us see at what point we have arrived after so many circuits, nor would I have you in doing so question me. For if you are about to enumerate concisely those things which I have granted, why is my response again desired?
Or is it that you would wantonly torture me by delays of joy, if we have in fact achieved any solid result? R. I will do that which I see that you wish, but attend most diligently. A. Speak now, here I am; why do you slay me? R. If everything which is in the subject always abides, it follows of necessity that the subject itself always abides. And every discipline is in the subject mind. It is necessary therefore that the mind should continue forever, if the science continues forever.
Now Science is Truth, and always, as in the beginning of this book Reason has convinced you, does Truth abide. Therefore the mind lasts forever, nor dead, could it be called the mind. He therefore alone can escape absurdity in denying the mind to be immortal, who can prove that any of the foregoing concessions have been made without reason.
Source: Soliloquies (New Advent)