L. Annaeus Seneca, On anger I, XI, 8    latin text    comment

Anger, therefore is not expedient even in battle or in war; for it is prone to rashness, and while it seeks to bring about danger, does not guard against it. The truest form of wisdom is to make a wide and long inspection, to put self in subjection, and then to move forward slowly and in a set direction.

from: Seneca, Moral Essays, with an English Translation by John W. Basore Ph. D., London – Cambridge (Massachusetts), William Heinemann Ltd – Harvard University Press, 1958 (The Loeb Classical Library)