On talking to yourself
Socrates, in Plato’s Theaetetus:
You, Theodorus, are a lover of theories, and now you innocently fancy that I am a bag full of them, and can easily pull one out which will overthrow its predecessor. But you do not see that in reality none of these theories come from me; they all come from him who talks with me. I only know just enough to extract them from the wisdom of another, and to receive them in a spirit of fairness. And now I shall say nothing myself, but shall endeavour to elicit something from our young friend.
Aristotle, Nicomachean Ethics IX.iv:
Therefore, since each of these characteristics [of friendship] belongs to the good man in relation to himself, and he is related to his friend as to himself (for his friend is another self), friendship too is thought to be one of these attributes, and those who have these attributes to be friends. Whether there is or is not friendship between a man and himself is a question we may dismiss for the present; there would seem to be friendship in so far as he is two or more, to judge from the afore-mentioned attributes of friendship, and from the fact that the extreme of friendship is likened to one’s love for oneself.
Wittgenstein, Philosophical Investigations, §270:
Let us now imagine a use for the entry of the sign “S” in my diary. I find out the following from experience: whenever I have a particular sensation, a manometer shows that my blood pressure is rising. This puts me in a position to report that my blood pressure is rising without using any apparatus. This is a useful result. And now it seems quite indifferent whether I’ve recognized the sensation correctly or not. Suppose that I regularly make a mistake in identifying it, this does not make any difference at all. And this alone shows that the supposition of this mistake was merely sham. (We, as it were, turned a knob which looked as if it could be used to adjust something in the machine; but it was a mere ornament not connected with the mechanism at all.)
And what reason do we have here for calling “S” the name of a sensation? Perhaps the kind of way this sign is employed in this language-game. And why a “particular sensation”: that is, the same one every time? Well, we’re supposing, aren’t we, that we write “S” every time.