According to Torah law, during war one is permitted to take a gentile woman captive and marry her, for it is written “When you go out to war against your enemies…and you take them captive, and you see among the captives a beautiful woman, and desire her and would take her for your wife, then you shall bring her home to your house…after that you may go in to her and be her husband, and she shall be your wife” (Deuteronomy 21:10-13). The scholars ask: Is a cohen also permitted to take a gentile woman captive? What are the issues under debate? On one hand, the Torah permitted everyone, with no exceptions, to take a captive, and did not specifically exclude the cohen. On the other hand, a cohen is forbidden to marry many types of women, including widows, defiled women, harlots, and converts who are considered harlots. For this reason one might think that the cohen is forbidden to take a captive. Answer: According to all, he is permitted the initial act of intercourse with the gentile captive. The reason for this is that the Torah permitted sexual intercourse with the captive woman because man’s nature in war is to desire the enemy’s women, and it is better to permit and set guidelines for such actions than to forbid them and lead the warrior into temptation. As the sages put it, “The Torah only spoke so to forestall the evil inclination.” But the sages were divided about what happens after his desire has been satisfied, if he wants to have sex with her another time and marry her. One of the sages, Rav, permitted the cohen to take a gentile woman captive and marry her, since the Torah permitted him the first act of intercourse, also permitting him, as an extraordinary case, to marry this woman. A different sage, Samuel, forbade the cohen marrying the captive woman, as she would be a convert and a cohen is not permitted to marry a convert.
(Often Talmudic discourse is presented in multiple versions because the text was distorted and forgotten. These alternate versions begin “Some say….”)

Some say the discussion amongst the sages is as follows: According to all the cohen is forbidden to marry the gentile captive, for she is considered to be a convert, forbidden to a cohen. What did the sages disagree about? They disagreed about whether a cohen is permitted an initial act of intercourse with the captive. According to the sage Rav it is permitted, for the Torah permitted the captive during war-time to forestall the evil inclination and a cohen has as much evil inclination as any man. The sage Samuel thought that even the initial act of intercourse is forbidden, since the cohen cannot marry her, and so may not satisfy his initial lusts.
(Babylonian Talmud, Tractate Kiddushin 21b)