the truth, his conduct would
endanger another man in detriment to virtue: and so it is in this
case.

Reply Obj. 4: The defect in a thing makes it of less value now than
it seems to be: but in the case cited, the goods are expected to be
of less value at a future time, on account of the arrival of other
merchants, which was not foreseen by the buyers. Wherefore the
seller, since he sells his goods at the price actually offered him,
does not seem to act contrary to justice through not stating what is
going to happen. If however he were to do so, or if he lowered his
price, it would be exceedingly virtuous on his part: although he does
not seem to be bound to do this as a debt of justice.
_______________________

FOURTH ARTICLE [II-II, Q. 77, Art. 4]

Whether, in Trading, It Is Lawful to Sell a Thing at a Higher Price
Than What Was Paid for It?

Objection 1: It would seem that it is not lawful, in trading, to sell
a thing for a higher price than we paid for it. For Chrysostom [*Hom.
xxxviii in the Opus Imperfectum, falsely ascribed to St. John
Chrysostom] says on Matt. 21:12: "He that buys a thing in order that
he may sell it, entire and unchanged, at a profit, is the trader who
is cast out of God's temple." Cassiodorus speaks in the same sense in
his commentary on Ps. 70:15, "Because I have not known learning, or
trading" according to another version [*The Septuagint]: "What is
trade," says he, "but buying at a cheap price with the purpose of
retailing at a higher price?" and he adds: "Such were the tradesmen
whom Our Lord cast out of the temple." Now no man is cast out of the
temple except for a sin. Therefore such like trading is sinful.

Obj. 2: Further, it is contrary to justice to sell goods at a higher
price than their worth, or to buy them for less than their value, as
shown above (A. 1). Now if you sell a thing for a higher price than
you paid for it, you must either have bought it for less than its
value, or sell it for more than its value. Therefore this cannot be
done without sin.

Obj. 3: Further, Jerome says (Ep. ad Nepot. lii): "Shun, as you would
the plague, a cleric who from being poor has become wealthy, or who,
from being a nobody has become a celebrity." Now trading would net
seem to be forbidden to clerics except on account of its sinfulness.
Therefore it is a sin in trading, to buy at a low price and to sell
at a higher price.

_On the contrary,_ Augustine commenting on Ps. 70:15, "Because