1. We arrive in our analysis at the third part of Christ's enunciation in the Sermon on the Mount (Mt 5:27-28). The first part was: "You have heard that it was said, 'You shall not commit adultery.'" The second: "But I say to you that everyone who looks at a woman lustfully....", is grammatically connected with the third part: "...has already committed adultery with her in his heart."
The method applied here, which is that of dividing or splitting Christ's enunciation into three parts which follow one another may seem artificial. However, when we seek the ethical meaning of the enunciation in its totality, the division of the text used by us may be useful. This is provided that it is applied not only in a disjunctive, but in a conjunctive way. This is what we intend to do. Each of the distinct parts has its own specific content and connotations, and we wish to stress this by dividing the text. But it must be pointed out at the same time that each of the parts is explained in direct relationship with the others. That referred in the first place to the principal semantic elements by which the enunciation constitutes a whole. These elements are: to commit adultery, to desire to commit adultery in the body, to commit adultery in the heart. It would be especially difficult to establish the ethical sense of desiring without the element indicated here last, that is adultery in the heart. The preceding analysis has already considered this element to a certain extent. However, a fuller understanding of "to commit adultery in the heart" is possible only after a special analysis.
2. As we have already mentioned, it is a question here of establishing the ethical sense. Christ's enunciation in Matthew 5:27-28 starts from the commandment: "Do not commit adultery", in order to show how it must be understood and put into practice, so that the justice that God-Yahweh wished as legislator may abound in it. It is in order that it may abound to a greater extent than appeared from the interpretation and casuistry of the Old Testament doctors. If Christ's words in this sense aim at constructing the new ethos (and on the basis of the same commandment), the way to that passes through the rediscovery of the values which—in the general Old Testament understanding and in the application of this commandment—have been lost.
That justice may abound
3. From this point of view also the formulation of the text of Matthew 5:27-28 is significant. The commandment "Do not commit adultery" is formulated as a prohibition which categorically excludes a given moral evil. It is well known that the same law (the Ten Commandments), as well as the prohibition "do not commit adultery," also include the prohibition, "Do not covet your neighbor's wife" (Ex 20:14, 17; Dt 5:18, 21). Christ did not nullify one prohibition with regard to the other. Although he spoke of desire, he aimed at a deeper clarification of adultery. It is significant that after mentioning the prohibition, "Do not commit adultery," as well known to his listeners, in the course of his enunciation he changed his style and the logical structure from the normative to the narrative-affirmative. When he said: "'Everyone who looks at a woman lustfully has already committed adultery with her in his heart," he described an interior fact, whose reality can easily be understood by his listeners. At the same time, through the fact thus described and qualified, he indicated how the commandment, "Do not commit adultery" must be understood and put into practice, so that it will lead to the justice willed by the legislator.
Establishing the sense
4. In this way we have reached the expression "has committed adultery in his heart." This is the key-expression, as it seems, for understanding its correct ethical meaning. This expression is at the same time the principal source for revealing the essential values of the new ethos, the ethos of the Sermon on the Mount. As often happens in the Gospel, here, too, we come up against a certain paradox. How can adultery take place without committing adultery, that is, without the exterior act which makes it possible to identify the act forbidden by the law? We have seen how much the casuistry of the doctors of the law devoted itself to defining this problem. But even apart from casuistry, it seems clear that adultery can be identified only in the flesh, that is, when the two, the man and the woman who unite with each other in such a way as to become one flesh (cf. Gn 2:24), are not legal spouses, husband and wife. What meaning, then, can adultery committed in the heart have? Is it not perhaps just a metaphorical expression the Master used to highlight the sinfulness of lust?
5. If we admitted this semantic reading of Christ's enunciation (Mt 5:27-28), it would be necessary to reflect deeply on the ethical consequences that would be derived from it, that is, on the conclusions about the ethical regularity of the behavior. Adultery takes place when the man and the woman who unite with each other so as to become one flesh (cf. Gn 2:24), that is, in the way characteristic of spouses, are not legal spouses. The detecting of adultery as a sin committed in the body is closely and exclusively united with the exterior act, with living together in a conjugal way. This referred also to the status of the acting persons, recognized by society. In the case in question, this status is improper and does not authorize such an act (hence the term "adultery").
The affirmative answer
6. Going on to the second part of Christ's enunciation (that is, the one in which the new ethos begins to take shape), it would be necessary to understand the expression, "Everyone who looks at a woman lustfully," in exclusive reference to persons according to their civil status. This is their status recognized by society, whether or not they are husband and wife. Here the questions begin to multiply. There can be no doubt about the fact that Christ indicated the sinfulness of the interior act of lust expressed through a way of looking at every woman who is not the wife of the one who so looks at her. Therefore we can and even must ask ourselves if, with the same expression, Christ admitted and approved such a look, such an interior act of lust, directed toward the woman who is the wife of the man who so looks at her.
The following logical premise seems to favor the affirmative answer to such a question. In the case in question, only the man who is the potential subject of adultery in the flesh can commit adultery in the heart. Since this subject cannot be the husband with regard to his own legitimate wife, therefore adultery in the heart cannot refer to him, but any other man can be considered guilty of it. If he is the husband, he cannot commit it with regard to his own wife. He alone has the exclusive right to desire, to look lustfully at the woman who is his wife. It can never be said that due to such an interior act he deserves to be accused of adultery committed in the heart. If by virtue of marriage he has the right to unite with his wife, so that the two become one flesh, this act can never be called adultery. Similarly the interior act of desire, dealt with in the Sermon on the Mount, cannot be defined as adultery committed in the heart.
Considering the results
7. This interpretation of Christ's words in Mt 5:27-28 seems to correspond to the logic of the Ten Commandments. In addition to the commandment, "Do not commit adultery" they also contain the commandment, "Do not covet your neighbor's wife." Furthermore, the reasoning in support of this interpretation has all the characteristics of objective correctness and accuracy. Nevertheless, good grounds for doubt remain as to whether this reasoning takes into account all the aspects of revelation, as well as of the theology of the body. This must be considered, especially when we wish to understand Christ's words. We have already seen what the "specific weight" of this expression is, how rich the anthropological and theological implications are of the one sentence in which Christ referred "to the beginning" (cf. Mt 19:8). These implications of the enunciation in the Sermon on the Mount in which Christ referred to the human heart confer on the enunciation itself also a "specific weight" of its own. At the same time they determine its consistency with evangelical teaching as a whole. Therefore we must admit that the interpretation presented above, with all its objective correctness and logical precision, requires a certain amplification and, above all, a deepening. We must remember that the reference to the human heart, expressed perhaps in a paradoxical way (cf. Mt 5:27-28), comes from him who "knew what was in man" (Jn 2:25). If his words confirm the Decalogue (not only the sixth, but also the ninth commandment), at the same time they express that knowledge of man, which—as we have pointed out elsewhere—enables us to unite awareness of human sinfulness with the perspective of the redemption of the body (cf. Rom 8:23). This knowledge lies at the basis of the new ethos which emerges from the words of the Sermon on the Mount.
Taking all that into consideration, we conclude that, as in understanding adultery in the flesh, Christ criticized the erroneous and one-sided interpretation of adultery that is derived from the failure to observe monogamy (that is, marriage understood as the indefectible covenant of persons), so also in understanding adultery in the heart, Christ takes into consideration not only the real juridical status of the man and woman in question. Christ also makes the moral evaluation of the desire depend above all on the personal dignity itself of the man and the woman; and this has its importance both when it is a question of persons who are not married, and—perhaps even more—when they are spouses, wife and husband. From this point of view it will be useful for us to complete the analysis of the words of the Sermon on the Mount, and we will do so the next time.
Source: L'Osservatore Romano