Letters 87.37

Besides, advantages may be predicated of animals, of men who are less than perfect, and of fools. Hence the advantageous may have an element of disadvantage mingled with it, but the word “advantageous” is used of the compound because it is judged by its predominant element. The good, however, can be predicated of the wise man alone; it is bound to be without alloy,

Seneca, Letters to Lucilius 87.37, translated by Richard Mott Gummere