Of all felicities, the most charming is that of a _firm_ and _gentle friendship_. It sweetens all our cares, dispels our sorrows, and counsels us in all extremities. Nay, if there were no other comfort in it than the bare exercise of so generous a virtue, even for that single reason, a man would not be without it. Beside, that it is a sovereign antidote against all calamities, even against the fear of death itself.

But we are not to number our friends by the _visits_ that are made us; and to confound the decencies of _ceremony_ and _commerce_ with the offices of _united affections_. Caius Gracchus, and after him Livius Drusus, were the men that introduced among the Romans the fashion of separating their visitants; some were taken into their _closet,_ others were only admitted into the _antechamber_: and some, again, were fain to wait in the _hall_ perhaps, or in the _court_. So that they had their _first_, their _second,_ and their _third_ rate friends; but none of them true: only they are called so in course, as we salute strangers with some title or other of respect at a venture. There is no depending upon those men that only take their compliment in their turn, and rather slip through the door than enter at it. He will find himself in a great mistake, that either seeks for a friend in a palace, or tries him at a feast.

Seneca's Morals of a Happy Life, Benefits, Anger and Clemency — Part 121

The great difficulty rests in the choice of him; that is to say, in the first place, let him be virtuous, for vice is contagious, and there is no trusting the sound and the sick together; and he ought to be a wise man too, if a body knew where to find him; but in this case, he that is least ill is best, and the highest degree of human prudence is only the most venial folly. That friendship where men’s affections are cemented by an equal and by a common love of goodness, it is not either hope or fear, or any private interest, that can ever dissolve it: but we carry it with us to our graves, and lay down our lives for it with satisfaction. Paulina’s good and mine (says our author) were so wrapped up together, that in consulting her comfort I provided for my own; and when I could not prevail upon her to take less care for me, she prevailed upon me to take more care for myself.

Seneca's Morals of a Happy Life, Benefits, Anger and Clemency — Part 121