You say "I cannot endure it: injuries are hard to bear." You lie.
<<You say, "I cannot endure it: injuries are hard to bear." You lie; for how can anyone not be able to bear injury, if he can bear to be angry? Besides, what you intend to do is to endure both injury and anger. Why do you bear with the delirium of a sick man, or the ravings of a madman, or the impudent blows of a child? Because, of course, they evidently do not know what they are doing: a man be not responsible for his actions, what does it matter by what malady he became so : the plea of ignorance holds equally good in every case.
"What then?" say you, “shall he not be punished?" He will be, even supposing that you do not wish it: for the greatest punishment for having done harm is the sense of having done it, and no one is more severely punished than he who is given over to the punishment of remorse.
In the next place, we ought to conder the whole state of mankind, in order to pass a just judgment on all the occurrences of life: for it is unjust to blame individuals for a vice which is common to all. The colour of an Æthiop is not remarkable among this own people, nor is any man in Germany ashamed of red hair rolled into a knot. You cannot call anything peculiar or disgraceful in a particular man if it is the general characteristic of his nation. Now, the cases which I have quoted are defended only by the usage of one out-of-the-way quarter of the world: see now, how far more deserving of pardon those crimes are which are spread abroad among all mankind.
We all are hasty and careless, we all are untrustworthy, dissatisfied, and ambitious: nay, why do I try to hide our common wickedness by a too partial description? we all are bad. Every one of us therefore will find in his own breast the vice which he blames in another. Why do you remark how pale this man, or how lean that man is? there is a general pestilence. Let us therefore be more gentle one to another: we are bad men, living among bad men: there is only one thing which can afford us peace, and that is to agree to forgive one another.
"This man has already injured me," say you, "and I have not yet injured him." No, but you have probably injured someone else, and you will injure him some day. Do not form your judgment by one hour, or one day: consider the whole tendency of your mind: even though you have done no evil, yet you are capable of doing it.>>
by Lucius Annaeus Seneca, 1st century c. 41 AD.
Book III, XXVI - Of Anger (De Ira), translated by Aubrey Stewart in 1889.