Institutio Oratoria

But as several words may often have the same meaning (they are called synonyms), some will be more distinguished, sublime, brilliant, attractive or euphonious than others. For as those syllables are the most pleasing to the ear which are composed of the more euphonious letters, thus words composed of such syllables will sound better than others, and the more vowel sounds they contain the more attractive they will be to hear.

But words require to be used in different ways. For example, horrible things are best described by words that are actually harsh to the ear. But as a general rule it may be laid down that the best words, considered individually, are those which are fullest or most agreeable in sound. Again, elegant words are always to be preferred to those which are coarse, and there is no room for low words in the speech of a cultivated man.

The choice of striking or sublime words will be determined by the matter in hand; for a word that in one context is magnificent may be turgid in another, and words which are all too mean to describe great things may be suitable enough when applied to subjects of less importance. And just as a mean word embedded in a brilliant passage attracts special attention, like a spot on a bright surface, so if our style be of a plain character, sublime and brilliant words will seem incongruous and tasteless excrescences on a flat surface.