I answer that, Just as by magnanimity a man has a mind to tend to great things, so by longanimity a man has a mind to tend to something a long way off. Wherefore as magnanimity regards hope, which tends to good, rather than daring, fear, or sorrow, which have evil as their object, so also does longanimity. Hence longanimity has more in common with magnanimity than with patience.
Nevertheless it may have something in common with patience, for two reasons. First, because patience, like fortitude, endures certain evils for the sake of good, and if this good is awaited shortly, endurance is easier: whereas if it be delayed a long time, it is more difficult. Secondly, because the very delay of the good we hope for, is of a nature to cause sorrow, according to Prov. 13:12, "Hope that is deferred afflicteth the soul." Hence there may be patience in bearing this trial, as in enduring any other sorrows. Accordingly longanimity and constancy are both comprised under patience, in so far as both the delay of the hoped for good (which regards longanimity) and the toil which man endures in persistently accomplishing a good work (which regards constancy) may be considered under the one aspect of grievous evil.
For this reason Tully (De Invent. Rhet. ii) in defining patience, says that "patience is the voluntary and prolonged endurance of arduous and difficult things for the sake of virtue or profit." By saying "arduous" he refers to constancy in good; when he says "difficult" he refers to the grievousness of evil, which is the proper object of patience; and by adding "continued" or "long lasting," he refers to longanimity, in so far as it has something in common with patience.
This suffices for the Replies to the First and Second Objections.