in contrast to the private feeling of pain, of which no one except the person who feels it is conscious. I am thus obliged to recognise more in existence than my own sensations and ideas—as much obliged as I am to recognise my sensations and ideas themselves when I am conscious of them. Only so can I find myself living in an environment that is capable of signifying the contemporaneous life, and some of the thoughts and feelings of other persons. In all this I am only falling back on the divine revelations of the common sense. They make me reject in conduct what is inconsistent with them; although this natural obligation is all the reason I can give in justification of my obedience.
It is thus that Reid recognises his right in reason to grasp realities that are independent of his individual self; and he thinks that he is doing this philosophically by getting rid of the unphilosophical supposition, that he needs to work his way to them by logical reasoning, founded on wholly inward impressions. The true philosophy of perception with him is to discharge the medium, and at once take the bull by the horns.
Some may think that the Inquiry represents wasted labour—that the 'metaphysical lunacy' which abolishes personal pronouns as meaningless words, and inconsistently reasons that all who reason must be fools, is at the best the idle intellectual pastime of persons who pretend to be universal sceptics—all which Reid has taken too seriously, and which at any rate by its self-contradiction refutes itself. For it asserts that assertion is impossible. It is an argument that concludes for the rejection of the postulates without which it is impossible for human beings to reason at all. It is a philosophy that destroys itself in destroying all philosophy. The suicide does not need to be put to death.
