picture in my mind

Friendship requires that rare mean betwixt likeness and unlikeness that piques each with the presence of power and of consent in the other party. Let me alone to the end of the world, rather than that my friend should overstep, by a word or a look, his real sympathy. I am equally balked by antagonism and by compliance. Let him not cease an instant to be himself. The only joy I have in his being mine, is that the not mine is mine. I hate, where I looked for a manly furtherance, or at least a manly resistance, to find a mush of concession. Better be a nettle in the side of your friend than his echo. The condition which high friendship demands is ability to do without it. That high office requires great and sublime parts. There must be very two, before there can be very one. Let it be an alliance of two large, formidable natures, mutually beheld, mutually feared, before yet they recognize the deep identity which, beneath these disparities, unites them.

- Ralph Waldo Emerson

I thought this an excellent description of what I'd always thought about friendship, the true kinds at least. What a delicate balance it is.