John Earle, Microcosmography or A Piece of the World Discovered in Essays and Characters, ed. by Harold Osborne (London: University Tutorial Press, 1933; 1628), p. 35:
Nothing easier than to create acquaintance: the mere being in company once does it; whereas friendship like children is engendered by a more inward mixture and coupling together; when we are acquainted not with their virtues only, but their faults, their passions, their fears, their shame, and are bold on both sides to make their discovery. And as it is in the love of the body, which is then at the height and full when it has power and admittance into the hidden and worst parts of it; so it is in friendship with the mind, when those verenda of the soul, and those things which we dare not shew the world, are bare and detected one to another.