Cicero

You may best understand this friendship by considering that, whereas the merely natural ties uniting the human race are indefinite, this one is so concentrated, and confined to so narrow a sphere, that affection is ever shared by two…

Now friendship may be thus defined: a complete accord on all subjects human and divine, joined with mutual goodwill and affection.

What can be more delightful than to have some one to whom you can say everything with the same absolute confidence as to yourself?

Is not prosperity robbed of half its value if you have no one to share your joy?

On the other hand, misfortunes would be hard to bear if there were not some one to feel them even more acutely than yourself.

Fire and water themselves, to use a common expression, are not of more universal use than friendship.

Such friendship enhances prosperity, and relieves adversity of its burden by halving and sharing it.

And great and numerous as are the blessings of friendship, this certainly is the sovereign one, that it gives us bright hopes for the future and forbids weakness and despair.

In the face of a true friend a man sees as it were a second self.

But such is the effect of the respect, the loving remembrance, and the regret of friends which follow us to the grave.

While they take the sting out of death, they add a glory to the life of the survivors.

Nay, if you eliminate from nature the tie of affection, there will be an end of house and city, nor will so much as the cultivation of the soil be left.

If you don't see the virtue of friendship and harmony, you may learn it by observing the effects of quarrels and feuds.

For if it were true that its material advantages cemented friendship, it would be equally true that any change in them would dissolve it.

But nature being incapable of change, it follows that genuine friendships are eternal.

For while the most fatal blow to friendship in the majority of cases was the lust of gold, in the case of the best men it was a rivalry for office and reputation, by which it had often happened that the most violent enmity had arisen…

Again, wide breaches and, for the most part, justifiable ones were caused by an immoral request being made of friends, to pander to a man's unholy desires or to assist him in inflicting a wrong.

A refusal, though perfectly right, is attacked by those to whom they refuse compliance as a violation of the laws of friendship.

Now the people who have no scruples as to the requests they make to their friends, thereby allow that they are ready to have no scruples as to what they will do for their friends; and it is the recriminations of such people which commonly…

I conclude, then, that the plea of having acted in the interests of a friend is not a valid excuse for a wrong action.

For, seeing that a belief in a man's virtue is the original cause of friendship, friendship can hardly remain if virtue he abandoned.

But if we decide it to be right to grant our friends whatever they wish, and to ask them for whatever we wish, perfect wisdom must be assumed on both sides if no mischief is to happen.

In the case of such men as these there is no point in saying that one of them would not have obtained such a request if he had made it; for they were men of the most scrupulous piety, and the making of such a request would involve a breach…

We may then lay down this rule of friendship--neither ask nor consent to do what is wrong.

This rule holds good for all wrong-doing, but more especially in such as involves disloyalty to the republic.