Courage, therefore, does not want the assistance of anger; it is sufficiently provided, armed, and prepared of itself.
We may as well say that drunkenness or madness is of service to courage, because those who are mad or drunk often do a great many things with unusual vehemence.

Ajax was always brave; but still he was most brave when he was in that state of frenzy: The greatest feat that Ajax e'er achieved Was, when his single arm the Greeks relieved.
Quitting the field; urged on by rising rage, Forced the declining troops again t'engage.
Shall we say, then, that madness has its use?
XXIV.

Examine the definitions of courage: you will find it does not require the assistance of passion.

Courage is, then, an affection of mind that endures all things, being itself in proper subjection to the highest of all laws; or it may be called a firm maintenance of judgment in supporting or repelling everything that has a formidable appearance, or a knowledge of what is formidable or otherwise, and maintaining invariably a stable judgment of all such things, so as to bear them or despise them; or, in fewer words, according to Chrysippus (for the above definitions are Sphaerus's, a man of the first ability as a layer-down of definitions, as the Stoics think.

But they are all pretty much alike: they give us only common notions, some one way, and some another).