David Hume’s ethical concepts stem from his belief, expressed in his Treatise of Human Nature, that “reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them.” In this assertion, Hume departs radically from nearly all Western thinkers before him, who saw reason as separate from and the intended master of the passions. Because of his unique ideas regarding the relationship between reason and the passions, Hume concluded that ethics cannot be a matter of reason and that ethics should instead flow from the emotions. Specifically, Hume believed that the feeling of sympathy is and should be the source of morality.
Annette Baier, in an evaluation of Hume from a feminist perspective, finds a place of agreement with Hume on this point. She sees Hume’s ideas as an early version of the views elucidated by ethical thinkers like Carol Gilligan, whose studies have found that men and women tend to think differently in moral matters, and that the latter tend to make ethical determinations based on sentiment and emotion. According to Baier, in positing that ethics should be based on sentiment and emotion, Hume advocates adopting a woman’s viewpoint in ethics.
As Hume’s views on ethics are such a radical departure from nearly all previous and most contemporary and subsequent thought it is not difficult to find a number of systems and ideas which run in direct contradiction to his or to imagine some of the arguments the proponents of these rival systems might launch against Hume’s ideas. One obvious flaw in his ideas, for instance, is that it does not offer a stable basis for ethical ideas and actions. Rather, all that is offered is the rather unstable basis of human emotion and individual preference. If mere sympathy and sentiment are the sole basis of ethics, the question is how this provides us with any motivation for radical change.
Think of someone with Hume’s ideas living in Nazi Germany, for instance. If this person has no personal sympathy for Jews, which is a very real possibility, he or she has no reason to intervene on their behalf, according to Hume. Even if this person has sympathy for them, he or she has no basis for the kind of self-sacrificing radical action that is called for in such extreme circumstances. In the end, Hume’s ethics are really a description of man at his worst and his most animal: a being of mere instinct and with the will only for survival and self-perpetuation.