Hume's Moral Theory

Hume's assertion that reason is and ought only to be the slave of the passions directly challenged the rationalist moral philosophy of his time. His argument that reason alone cannot motivate moral action represents a fundamental critique of philosophers who maintained that reason could both discover moral truths and motivate moral behavior. This essay will examine Hume's arguments against reason as a moral motivator and evaluate their strengths and limitations.

Hume limited the scope of reason to two functions: examining relations of ideas and establishing matters of fact. Reason, he argued, can determine logical truths and factual accuracy. It can also calculate the most efficient means to achieve a desired end. However, reason itself is inert; it lacks the power to initiate action. To illustrate, consider the process of building a house. Reason can determine the optimal structural design (relations of ideas) and the best materials to use based on cost and durability (matters of fact). Reason can also calculate the steps and resources needed to complete the construction. Yet, reason alone does not motivate the builder to begin constructing the house. The desire to build a house, the purpose itself, originates from a passion or want, not from reason. Reason is instrumental in achieving the goal, but not in setting the goal itself.

Hume further emphasized the distinct impact of moral judgments compared to purely rational conclusions. Moral judgments, when we deem something virtuous or vicious, directly influence our actions. Judging an act as virtuous prompts approval and inclination towards it, while judging it as vicious generates disapproval and avoidance. This immediate motivational force is absent in purely rational judgments. For example, consider a mathematical theorem proved by reason. Understanding and accepting the theorem as rationally valid does not automatically compel any specific action. One might appreciate its elegance or intellectual value, but this appreciation is a sentiment, not a direct outcome of reason itself. In contrast, judging an act of charity as virtuous is likely to evoke a feeling of approval and perhaps even inspire similar charitable behavior. This inherent motivational quality of moral judgment, Hume argued, points to a source beyond reason. He also highlighted the “is-ought” problem, demonstrating that normative statements about what ought to be cannot be logically derived solely from descriptive statements about what is. This gap suggests that morality requires a foundation other than pure reason.

Instead of reason, Hume located the source of moral motivation in moral sentiments. These are feelings of approval or disapproval that arise from our capacity for sympathy, the ability to share and understand the feelings of others. Sympathy allows us to experience vicariously the pleasure or pain of others. Actions that tend to promote happiness and reduce suffering evoke feelings of approval, while actions causing harm elicit disapproval. These emotional responses, rooted in sympathy, are the motivating forces behind moral behavior. For example, witnessing someone helping another in distress typically evokes a feeling of approval. This feeling is not a rational deduction but an emotional response stemming from our sympathetic understanding of the alleviated suffering and increased happiness. This feeling of approval, in turn, can motivate us to act similarly in future situations.

Hume's sentiment-based account explains the immediate link between moral judgment and action without resorting to abstract rational intuitions. It also aligns with observations of moral behavior, which often involves emotional engagement and empathy rather than abstract reasoning. Empirical evidence suggests that people are more likely to act morally when emotionally moved by a situation than when presented with purely rational arguments for moral conduct.

However, Hume's theory faces significant challenges. One fundamental challenge involves situations where individuals act morally without apparent strong emotions. Consider a soldier following orders in a dangerous situation. While Hume might explain such behavior through his concept of 'calm passions' - stable dispositions shaped by habit and custom - this explanation raises problems for his core thesis about sentiment and motivation. If moral dispositions can operate without felt emotion, as in the soldier's case, perhaps reason plays a more fundamental role than Hume acknowledges. The very notion of calm passions, which function more like rational principles than feelings, suggests that the boundary between reason and sentiment may not be as clear as Hume claims. His attempt to classify all motivating factors as passions risks stretching the concept of sentiment beyond recognition.

Another challenge concerns the potential variability of moral sentiments. Emotions are known to be influenced by personal biases, proximity, and immediate circumstances. If morality is based solely on sentiment, moral judgments might become unstable and subjective. Hume addressed this through the concept of the 'general point of view.' Rather than involving purely individual rational reflection, this perspective emerges through social discourse and shared moral language. As we engage in moral conversation with others, we develop common standards of praise and blame that transcend individual biases. The general point of view represents these shared standards that arise from collective experience rather than abstract rational deliberation. For instance, while our immediate sentiment might favor helping a friend over a stranger, our participation in moral discourse helps us recognize broader social values that moderate such partiality. This social correction of sentiment differs from the kind of rational reflection emphasized by moral rationalists.

Furthermore, distinguishing moral sentiments from other motivating emotions poses a challenge. Not all emotions are moral. Fear, anger, or personal desires can motivate actions, but are not inherently moral motivators. Hume argued that moral sentiments are specifically those arising from sympathy and the consideration of general utility – actions promoting overall well-being. However, determining "general utility" itself requires rational deliberation about consequences and societal effects. Reason is necessary to assess which actions truly contribute to the greater good, thus playing a role in identifying and validating moral sentiments.

Finally, Hume's emphasis on sentiment creates particular difficulties for moral education. While he acknowledges that natural sentiments require correction through the general point of view, his account of this correction process remains deeply problematic. If moral judgments ultimately rest on feeling rather than reason, how can we justify preferring some sentiments over others? The very idea of 'correcting' sentiments seems to presuppose some rational standard of correction that Hume's theory explicitly rejects. Moreover, successful moral education often involves appealing to principles and reasons - consider how we teach children about fairness or respect for others. These educational practices suggest that reason plays a more fundamental role in moral development than Hume's theory can accommodate.

These challenges suggest that while Hume effectively demonstrated the limitations of pure moral rationalism, his solution may overcorrect by making sentiment too fundamental. His sharp distinction between reason and passion, while useful for critiquing rationalism, appears unable to capture the complex interplay between thinking and feeling in moral life. The very practices he describes - adopting the general point of view, correcting natural sentiments, developing stable moral dispositions - seem to require a more substantial role for reason than his theory allows.

In conclusion, Hume convincingly shows that reason alone cannot motivate moral action, delivering a powerful critique of rationalist moral philosophy. However, his alternative account, grounding morality primarily in sentiment, faces serious difficulties. The existence of calm passions, the processes of moral education, and the need for stable moral judgments all suggest that reason may play a more fundamental role than Hume acknowledges. Moreover, his emphasis on sentiment risks making morality too subjective, despite his attempts to ground it in shared human nature and social discourse. While Hume's critique of pure rationalism stands, his sharp separation of reason and passion may ultimately be too rigid to capture the true complexity of moral motivation and judgment.