In a given situation there are an infinite number of ways in which a man can act. Which of these actions he chooses to take depends on who he is as an individual. This point is obvious, but what is not so obvious is what motivates him to make the choices he does. It is possible that he reasons what the most logical choice is, or it could be that his desires motivate his actions. I will examine the arguments presented by Nagel, Rawls, and Hume to show the extremes and compromises of this argument.

Thomas Nagel is a major advocate that actions are influenced entirely by reason. The basis for his argument is that he believes in objective morality, the idea that in a given situation there is one choice, which is the universally most morally correct choice to be made. From this belief stems his argument that only through reason can we logically deduce what that one correct action is, at which point desires will have no influence upon us. A man should strive to see the world from as much of a detached view as possible if he is to be able to accurately choose the correct action. He claims that “in order to pursue objectivity we must take up a new, comprehensive viewpoint after stepping back.” Whenever a decision is to be made we must take our beliefs, step back from our personal point of view, determine the set of values that applies to the situation, and then change our beliefs to better fit those values. In this way we can always use reason to choose the most morally correct action.

Rawls similarly believes in objective morality, but does not share Nagel’s belief that decisions should stem entirely from a detached analysis of reason. Rawls believes that the only way for a person to live a good life is to figure out what his desires are and then come up with a rational plan for life which will allow him to best achieve his goals. This is only true if “his interests and aims are rational, and it is appropriate to take them as stopping points in making judgments.” From that point on actions can be deduced rationally by simply evaluating each possible action and seeing which corresponds the most with the rational plan. It is important that these actions not be corrupted by desires while they are being made, because this could lead to irrational decisions. It is, however, important that the basis of all these rational decisions be the individuals end goals and desires. So Rawls, like Nagel, believes that reason is the only way to come to a correct decision in a situation, but he does not share Nagel’s belief that the basis for these decisions should be completely objective and detached from the person.

Hume rejects all of Nagel’s and Rawls’ base assumptions, especially the existence of objective morality. Hume believes that all morality is subjective, that there is no answer to a moral question that is more “right” than another. If reason is simply an evaluative system that allows man to come to conclusions than obviously it cannot influence our actions if no conclusion is the right one. Rather, Hume believes that our decisions are motivated entirely by desires, which he refers to as passions, and that these desires are in no way influenced or inhibited by reason. Once a desire has been established we can then use reason to determine the best way of fulfilling this desire. Reason, according to Hume, is a system that deduces cause and effect. He proves that only passions and never reason can influence our actions by pointing out that “it can never in the least concern us to know, that such objects are cause, and such others effects, if both the causes and effects be indifferent to us.”

These three philosophers show the wide range of theories on this subject. What their arguments boil down to is that whether or not reason can influence actions is directly related to how whether or not there is a truly ‘right’ decision to be made. As reason is an evaluative system then it can only influence a correct action if there is a correct action to be made. If every action is equally correct than only passions can influence them. The middle ground is that if there is a correct choice, but it is unique to the individual, then the individual’s goals and desires must define that action and the individual’s reason must determine what that action is. This debate does not center around whether or not reason influences action, but is dependant on the base argument of whether or not a correct action exists.