8 But although patience be a virtue of the mind, yet partly the mind exercises it in the mind itself, partly in the body. In itself it exercises patience, when, the body remaining unhurt and untouched, the mind is goaded by any adversities or filthinesses of things or words, to do or to say something that is not expedient or not becoming, and patiently bears all evils that it may not itself commit any evil in work or word. By this patience we bear, even while we be sound in body, that in the midst of the offenses of this world our blessedness is deferred: of which is said what I cited a little before, “If what we see not we hope for, we do by patience wait for it.”
By this patience, holy David bore the revilings of a railer, and, when he might easily have avenged himself, not only did it not, but even refrained another who was vexed and moved for him; and more put forth his kingly power by prohibiting than by exercising vengeance. Nor at that time was his body afflicted with any disease or wound, but there was an acknowledging of a time of humility, and a bearing of the will of God, for the sake of which there was a drinking of the bitterness of contumely with most patient mind.
This patience the Lord taught, when, the servants being moved at the mixing in of the tares and wishing to gather them up, He said that the householder answered, “Leave both to grow until the harvest.” That, namely, must be patience put up with, which must not be in haste put away. Of this patience Himself afforded and showed an example, when, before the passion of His Body, He so bore with His disciple Judas, that ere He pointed him out as the traitor, He endured him as a thief; and before experience of bonds and cross and death, did, to those lips so full of guile, not deny the kiss of peace. All these, and whatever else there be, which it were tedious to rehearse, belong to that manner of patience, by which the mind does, not its own sins but any evils so ever from without, patiently endure in itself, while the body remains altogether unhurt.
But the other manner of patience is that by which the same mind bears any troubles and grievances whatsoever in the sufferings of the body; not as do foolish or wicked men for the sake of getting vain things or perpetrating crimes; but as is defined by the Lord, “for righteousness' sake.” In both kinds, the holy Martyrs contended. For both with scornful reproofs of the ungodly were they filled, where, the body remaining intact, the mind has its own (as it were) blows and wounds, and bears these unbroken: and in their bodies they were bound, imprisoned, vexed with hunger and thirst, tortured, gashed, torn asunder, burned, butchered; and with piety immovable submitted unto God their mind, while they were suffering in the flesh all that exquisite cruelty could devise in its mind.
Source: On Patience (New Advent)