Friendship is one mind in two bodies.

A friend is one soul abiding in two bodies.

Friendship makes you feel as one with your friend.

Friendship is the positive and unalterable choice of a person whom we have singled out for qualities that we most admire.

Friendship, as has been said, consists in a full commitment of the will to another person with a view to that person's good.

La amistad es una mente en dos cuerpos.

Friendship is a social relation of a kind that is beyond all "ethics," you see, and if you ever think of it in terms of ethics you misunderstand it. It is a great pleasure between two, very different from sexual pleasure between man and woman, but of the same species, in that it is pleasant, and never feels like "ethics," which is for cows.

I am also prepared to admit the value of an enduring friendship and faithfulness between two persons of the same sex. Friendship has always been held in great honour in the ancient world, perhaps more so than today, even though it was mostly understood in the context of that transcending of the purely physical sphere I mentioned above, to be a union of minds and hearts.

"Friendship arises out of mere Companionship when two or more of the companions discover that they have in common some insight or interest or even taste which the others do not share and which, till that moment, each believed to be his own unique treasure (or burden). The typical expression of opening Friendship would be something like, "What? You too? I thought I was the only one."
... It is when two such persons discover one another, when, whether with immense difficulties and semi-articulate fumblings or with what would seem to us amazing and elliptical speed, they share their vision - it is then that Friendship is born. And instantly they stand together in an immense solitude."

Friends are true Twins in Soul; they Sympathize in every thing, and have the Love and Aversion. One is not happy without the other, nor can either of them be miserable alone. As if they could change Bodies, they take their turns in Pain as well as in Pleasure; relieving one another in their most adverse Conditions.What one enjoys, the other cannot Want. Like the Primitive Christians, they have all things in common, and no Property but in one another.

A friend is one to whom one may pour out the contents of one's heart, chaff and grain together, knowing that gentle hands will take and sift it, keep what is worth keeping, and with a breath of kindness, blow the rest away.

A friend is one who knows you and loves you just the same.

A friend is a person with whom I may be sincere. Before him I may think aloud. I am arrived at last in the presence of a man so real and equal, that I may drop even those undermost garments of dissimulation, courtesy, and second thought, which men never put off, and may deal with him with the simplicity and wholeness with which one chemical atom meets another.

Friendship arises out of mere companionship when two or more of the companions discover that they have in common some insight or interest or even taste which the others do not share and which, till that moment, each believed to be his own unique treasure (or burden). The typical expression of opening Friendship would be something like, "What? You too? I thought I was the only one."