Alexander Solzhenitsyn (1918-2008), Nobel Lecture
, § 4:
From time immemorial man has been made in such a way that his vision of the world, so long as it has not been instilled under hypnosis, his motivations and scale of values, his actions and intentions are determined by his personal and group experience of life. As the Russian saying goes, "Do not believe your brother, believe your own crooked eye." And that is the most sound basis for an understanding of the world around us and of human conduct in it.
Cf. Euripides, Helen
580 (tr. David Kovacs):
Who but your eyes should be your teacher?
τίς οὖν διδάξει σ᾽ ἄλλος ἢ τὰ σ᾽ ὄμματα;