In a sentence, what is a parallel structure

Parallel structure means using the same pattern of words to show that at least two ideas are equally important as each other. Parallel structure can be used to create a rythem or a pattern in certain types of sentences.

evertheless he ought to be slow to believe and to act, nor should he himself show fear, but proceed in a temperate manner with prudence and humanity, so that too much confidence may not make him incautious and too much distrust render him intolerable.

explanation:

im not 100 percent sure but i think its a