Jesus’ sufferings could not have been the most painful of all because, as the Stoics say, moral virtue mitigates pain and Christ was virtuous.
Thomas responds to this objection (III, 46, 6) by insisting that the Stoics are wrong: “the Stoics held all sadness to be unprofitable, they accordingly believed it to be altogether discordant with reason, and consequently to be shunned altogether by a wise man. But in very truth some sadness is praiseworthy, as Augustine proves . . . -namely, when it flows from holy love, as, for instance, when a man is saddened over his own or others’ sins. Furthermore, it is employed as a useful means of satisfying for sins, according to the saying of the Apostle: ‘The sorrow that is according to God worketh penance, steadfast unto salvation.’ And so to atone for the sins of all men, Christ accepted sadness, the greatest in absolute quantity, yet not exceeding the rule of reason.”