Plato Apology 31

[31] Such another is not likely to come to you, gentlemen; but if you take my advice, you will spare me. But you, perhaps, might be angry, like people awakened from a nap, and might slap me, as Anytus advises, and easily kill me; then you would pass the rest of your lives in slumber, unless God, in his care for you, should send someone else to sting you. And that I am, as I say, a kind of gift from the god, 31b you might understand from this; for I have neglected all my own affairs and have been enduring the neglect of my concerns all these years, but I am always busy in your interest, coming to each one of you individually like a father or an elder brother and urging you to care for virtue; now that is not like human conduct. If I derived any profit from this and received pay for these exhortations, there would be some sense in it; but now you yourselves see that my accusers, though they accuse me of everything else in such a shameless way, have not been able to work themselves up to such a pitch of shamelessness 31c as to produce a witness to testify that I ever exacted or asked pay of anyone. For I think I have a sufficient witness that I speak the truth, namely, my poverty.
  Perhaps it may seem strange that I go about and interfere in other people’s affairs to give this advice in private, but do not venture to come before your assembly and advise the state. But the reason for this, as you have heard me say 31d at many times and places, is that something divine and spiritual comes to me, the very thing which Meletus ridiculed in his indictment. I have had this from my childhood; it is a sort of voice that comes to me, and when it comes it always holds me back from what I am thinking of doing, but never urges me forward. This it is which opposes my engaging in politics. And I think this opposition is a very good thing; for you may be quite sure, men of Athens , that if I had undertaken to go into politics, I should have been put to death long ago and should have done 31e no good to you or to myself. And do not be angry with me for speaking the truth; the fact is that no man will save his life who nobly opposes you or any other populace and prevents many unjust and illegal things from happening in the state. 32a A man who really fights for the right, if he is to preserve his life for even a little while, must be a private citizen, not a public man.