For no man is voluntarily bad; but the bad become bad by reason of an ill disposition of the body and bad education, things which are hateful to every man and happen to him against his will.
dispositionquotes
A man may possess the disposition without its producing any good result.
The one necessary thing – a person must have one or the other. Either a cheerful disposition by nature, or a disposition made cheerful by art and knowledge.
art / disposition / knowledge