What is the relationship between the person and the common good? This question has been asked in the movies Star Trek II: The Wrath of Khan and Star Trek III: The Search For Spock. In each film, the answer given seems to contradict each other. Spock, it appears, represents the argument from a logical standpoint, while his friends seem to come to the discussion on an emotive level. Spock believes, when the common good is threatened, the needs of the many outweigh the needs of the few or the one, while Kirk suggests that the needs of the few can trump the needs of the many. For those unfamiliar with either movie (whoever that could be?!), let us briefly look at how they addressed this question before we examine what we get from them and see if there might be some way out an apparently contradictory message from the films.
In Star Trek II, Spock finds the Enterprise disabled. Unless it is able to move, it will be destroyed. The engines of the ship are disabled. Only he can bring them back to working order in time, though at the cost of his life. For Spock, when confronted with such a dilemma, there was no real question as to what he should do: he must save the Enterprise, he must work for the common good, even if it meant his own death.
Spock must die in order for the Enterprise and her crew could live. Spock willingly sacrificed himself, though he did leave himself a way out, a way for his consciousness to continue in the head of Dr. McCoy. Due to the circumstances around his death, there would come about a way for Spock’s consciousness to be returned to his body, for him to live again – but it would require great risk for Spock’s friends. They were forbidden to do what they wanted to do, and so they knew officials would retaliate against them if they went ahead and tried to bring Spock back to life. Should they risk it? The answer is yes, and the answer is because Spock’s needs, the needs of the one, outweigh the needs of Spock’s friends.
Spock must live, no matter the cost.
The question of which takes precedence, the personal good or the common good, is not as straightforward as it might appear. The answer really depends upon the good which is being willed, as Henry of Ghent suggests:
One must say that it is necessary here to make distinctions about the good and about a personal good and the common good, because it is a temporal good that principally pertains to the body and it is a spiritual good that principally pertains to the soul. Likewise, there is a personal good that is included in the common good, and there is a personal good that is not included in it. 
When dealing with the common good, it is often erroneous to suggest that one’s personal good is in conflict with the common good. The two often go together; by looking for and promoting the common good, one usually helping oneself. This is true both temporally as well as spiritually. Clearly, some might suggest one could get a greater temporal good for oneself if one neglects the common good, but that ends up being an argument to promote selfishness, and the end result might be a greater temporal good, but a lesser spiritual good. In such a situation, because spiritual goods are more worthwhile than temporal goods, one can only say such an attitude leads towards a lessening of one’s own overall good and so that should be reason enough to overcome such selfishness.
However, this is the easiest kind of analysis one can do, and it is often this kind of analysis which overshadows the questions surrounding the personal and common good. As we have seen, there are two types of goods to consider: temporal goods and spiritual goods. We end up with several different possibilities which we must face: temporal personal good over temporal common good; temporal personal good over spiritual common good; spiritual personal good over temporal common good; and spiritual personal good over a spiritual common good. Even in these situations, the answer is not always simple; it is not always the case that the common good wins out. Thus Henry of Ghent says one can hold out for a greater spiritual good for oneself over the needs of the common spiritual good:
If, however, each good is spiritual, in that case one should rather procure his own personal good, because anyone ought to will for himself a small amount of the good of grace or glory on account of its eternal perseverance rather than the greatest amount of good for the neighbor, just as one ought to will to be saved alone and that all the rest be condemned rather than the opposite.
The problem with this answer is that it assumes the possibility that one can work for the spiritual common good while finding oneself condemned because one worked for such a common good. This does not appear to be likely: the more good one does for one’s neighbor, the more one multiplies the good in one’s own personal life. Being charitable, one gains God:
If you possess charity, you have God; and if you have God, what do you not possess? If a rich man does not have charity, what does he have? If a poor man has charity, what does he lack? Perhaps you think that he is a rich man whose coffers are full of gold, and he is not rich whose conscience is full of God. That is not true, brethren. A man really seems to be rich, if God deigns to dwell in him. Now what can you be ignorant of in the Scriptures if charity, that is, God, begins to take possession of you? What good works can you fail to perform, if you deserve to carry the fountain of good works in your heart?
Thus to die to the self, to give over and seek after the spiritual good of the community ultimately lifts oneself up and provides the greatest increase in one’s own personal spiritual good. Though, logically, one could think of the idea of losing one’s salvation for the sake of others, the one who willingly seeks after the salvation of others, with faith and trust in God, will find their own salvation. With spiritual goods, working for the increase of the spiritual common good will only bring in a measurable increase in one’s own spiritual good. Thus, there is no conflict here.
The major places of conflict are when one’s personal temporal good is in conflict with a social temporal good, or when one’s personal spiritual good is in conflict with a temporal social good. For the first, one must ask about the conflict, as to whether or not the personal or social goods are necessary ones; when the personal good (being able to eat) is in conflict with an unnecessary social temporal good (everyone else is able to eat, but less luxuriously if one promotes one’s own temporal good), then the personal good trumps the social good. This explains why one who is starving can take food, even if society views it as stealing, and not suffer a spiritual stain because of one’s action. The needs of the one in this instance outweigh the social good. On the other hand if the personal temporal good is something unnecessary while the social temporal good is something necessary, then the social good trumps the personal good. And if it is more or less even, the social good, because it includes the personal good, must be the one pursued. Thus, Henry of Ghent says:
In that case, as I think, one should still procure the common good, because, even if one’s own temporal good is not included in the common temporal good, it is still impossible that one’s personal spiritual good is not included as a result of the merit of the one who procures that good, and one should procure his own personal spiritual good, other things being the same, more than his own personal temporal good.
One who sacrifices one’s own personal, temporal goods for the sake of the common good gains a greater spiritual good, and so, while there is a temporal loss, there is an eternal gain. This is not to say that the temporal goods are to be dismissed as meaningless; when there is no challenge, one should promote the personal temporal good as well, because we are made for worldly, physical life and not just a life of the spirit.
Now the question of one’s personal spiritual good over the social temporal good, the answer is always, to promote the spiritual good though in doing so with the desire to promote, the best one can, the common temporal good and the common spiritual good. The holy martyrs present to us the ideal here: they sought a transformation of the social system, but they were unwilling to engage spiritual evil even if it might have strengthened and aided the temporal social order. The personal spiritual good is the desire to do all that one can do which is good, not just for oneself, but for society; helping a defective system thrive might help give more people temporal goods, but in the end, even those temporal goods will be lost. By giving voice to the error of the system itself, one is ultimately promoting the spiritual and temporal common good, though of course, in the immediate sense, the temporal common good is rejected.
This brings us back to Spock and Star Trek. In both movies, the answer given is the legitimate answer to different questions. Equivocation is necessary in order to make the answers conflict. In the first case, Spock is dealing with the necessary needs of the common good over the necessary needs of the personal good; in giving up his life, he points not only to the fact that the common good in such a situation must be followed, but also, the personal spiritual good must also be followed over the personal temporal good. Spock sacrifices himself, saving his spirit while letting his body die; having McCoy become a vessel for his consciousness is a way to present this fact so that a common moviegoer can understand the gain Spock achieves from his act. In the situation around Kirk, Kirk is pointing out that the needs of the personal temporal good must be met, even if it means the social temporal good is diminished – as long as the diminishment does not destroy and eliminate the common social good itself. Society, indeed, can find a temporary lessening of the common temporal good can lead to the improvement of the personal good of someone whose contributions will later help society transcend itself; that is, by risking themselves to help Spock, Spock’s friends ultimately help themselves by making sure Spock will be able to contribute all he has to offer for the common good. The Klingons and Romulans would end up having better relations with Star Fleet as a result of the temporary reduction of the temporal common good, bringing, in the end, a greater and more triumphant common good in return.
When the common good is threatened, and Spock’s death can save the common good, Spock must die. When the common good is not radically threatened, but Spock’s personal good is, Spock must live. Both are true statements, and, in the end, there is no real conflict between Star Trek II and Star Trek III. They show two different ways the personal and common good are to deal with each other, and show why prudence is important when dealing with moral questions. Both Spock and Kirk, in reality, give logical answers.
 Henry of Ghent, Quodlibetal Questions on Moral Problems. Trans. Roland Teske, S.J. (Milwaukee: Marquette University Press, 2005), 25.
 Ibid., 26.
 St. Caesarius of Arles, “Sermon 22” in St. Caesarius of Arles: Sermons 1-80. Trans Sister Mary Magdalene Mueller, O.S.F. (New York: Fathers of the Church, Inc., 1956), 115.
 We could explore other conflicts, since they do exist, but what we say here should be able to help one find the solution to other such conflicts.
 Henry of Ghent, Quodlibetal Questions, 26.