• The Science of Human Nature
• Sentimentalism
  • The Combat of Reason and the Passions
  • The Combat of Duty and Inclination
• The Self-Vindicatory Nature of the Sentimentalist Explanation of Morals
  • Explanation and Justification
  • Self-Knowledge and Moral Transformation

The Science of Human Nature

Much of the Treatise is structured around a contrast between two kinds of inquiry. Metaphysical inquire investigates the supersensible natures of things—such as the necessary connection between cause and effect or a self that underlies human perceptions, whereas Hume’s moral science investigates human nature on the basis of its sensible effects. Given the cautious observation of humans and human activity, the moral scientist seeks to explain these diverse phenomena in terms of a few general principles. Hume ultimately despairs of the metaphysical speculation about the supersensible nature of things. Hume doesn’t deny that things have supersensible natures, he claims only that there is no point in speculating about this since we lack the means to know these things. The prospects for Hume’s new science of human nature are more bright. Hume believes for example that his theory of the passions displays many of the virtues that Newton’s theory of matter displays. Each displays a theoretical economy—each is an empirical inquiry that explains diverse phenomena in terms of a few general principles

Hume’s new science of human nature, like Newton’s theory, is primarily descriptive and explanatory, as opposed to prescriptive and justificatory. Moral science seeks to describe diverse phenomena of human psychology and activity and explain these in terms of a few general principles. Moral science does not seek to prescribe that we make certain moral judgments. Hume is not recommending moral judgments to his audience—he takes it for granted that there is a large measure of agreement at least about fundamental matters of morals between himself and his audience. So Hume is not engaged in any casuistry, nor is he offering a moral sermon or panygeric to Virtue. Nor does moral science seek to justify the moral judgments that we actually do make. Hume is not trying to justify the moral judgments we make. He is not trying to persuade a moral skeptic. Again he takes it for granted that there is a large measure of moral agreement between himself and his audience. Hume is explicit about this contrast when he describes as an anatomist of morals and contrasts this with he Painter of Virtue. Hume worries that: “Any warm Sentiment of Morals, I am afraid, would have the Air of Declamation amidst abstract Reasonings, & wou’d be esteem’d contrary to good Taste.”

Not only is Hume’s moral science descriptive and explanatory, but the explanations it seeks are naturalistic. Hume seeks to give an account of human morality as a natural phenomena—as arising from human nature and our place in nature. He thus rejects any attempt to give a theological foundation to morality of a kind that natural law theorists recommended. Not only does the science of human nature offer naturalistic explanations for the moral distinctions that we make but the naturalistic explanations that Hume ultimately offers takes a particular form: Hume offers a sentimentalist explanation of the moral distinctions we make. According to sentimentalism moral distinctions are determined not by reason but by moral sense.

Sentimentalism

The fundamental question that separated pre-Humean rationalists, such as Malebranche, Clark and Cudworth, and pre-Humean sentimentalists, such as Shaftesbury and Hutcheson is:

Whether moral distinctions are determined by reason or internal sentiment?

Given Hume’s metaphysics of mind, this question reduces to the question:

Whether ‘tis by means of our ideas or impressions we distinguish betwixt vice and virtue, and pronounce an action blameable or praise-worthy?

Sentimentalism, however, is apparently in tension with the phenomenology of moral experience at least as conceived by the vulgar.

First, there is an ancient tradition of speaking of the combat of reason and the passions. We are inclined to speak of a person who, in the throws of violent emotion, acts contrary to his interests as being “out of his senses”—the suggestion being that the operation of reason (involving, in this instance, the abilities to recognize what is in one’s best interest and to take relevant steps to promote, or at least not frustrate, that interest) has been disordered by the turbulence of felt emotion. The image of reason and passion’s combat encourages a number of closely related claims:

• Reason and the passions can both determine the will.
• The passions can oppose reason’s determination of the will, and reason can oppose the passions’ determination of the will.
• Reason ought to determine the will.
• A person is only virtuous to the extent that his will is determined by reason.

Sentimentalism is inconsistent with these claims. Hume does not flatly deny this aspect of moral phenomenology. Hume concedes that talk of the the combat of reason and the passions is apt if ultimately misleading. Hume maintains that the moral experience of the vulgar registers something even if the vulgar are prone to misconceive it in a certain way.

Second, a distinct if related feature of moral phenomenology is, as Kant will subsequently describe it, the conflict of duty and inclination. Duty and inclination can conflict. Sometimes duty requires that we act for some end for which we are not inclined or even disinclined depending on the contingent configuration of our passions and the contingent circumstances in which they operate. It is not just that duty and inclination conflict, but duty can be a motive to act in the absence of positive inclination and in the face of negative inclination. Moreover, this motive to duty can override or even cancel any nonmoral incentive. The motive to duty seems to be independent of any inclination or passion. This is part of what Kant means when he describes them as categorical imperatives. Again this seems inconsistent with sentimentalism. How can duty be determined by sentiment given the categorical nature of its demands? Here again, Hume maintains that the moral experience of the vulgar registers something even if the vulgar are prone to misconceive it.

Let’s briefly review these two reconciliationist projects

The Combat of Reason and the Passions

When philosophers and the vulgar claim that reason can determine the will and oppose the passions’ determination of the will, they mistake the operation of certain calm passions for the operation of reason. Recall that the passions are either calm or violent. Calm passions “though they be real passions produce little emotion in the mind and are more known by their effects than by the immediate feeling of sensation” (Treatise, 2.3.3.8). In this way, they differ from violent passions which can be known by immediate feeling or sensation. Since reason itself exerts little sensible emotion, it is natural to mistake the operation of the calm passions, for the operation of reason.

What the vulgar call “passions” are really violent emotions that arise from any good or evil that excites that appetite. What the vulgar call “reason” are really emotions that operate more calmly and occasion no disorder. The calm passions include, among others, the general appetite to good and aversion to evil. Consider now the case of someone preferring the destruction of the whole world to the scratching of his finger. In this case, a strong violent emotion has overcome the weak general appetite for the good that operates more calmly and occasions no such disorder. This preference is not contrary to reason in the strict and philosophical sense. Rather, this preference occasions the distinctive pain of disapprobation from a more general point of view in characters where the calm passions operate more strongly. When the vulgar describe the preference for the destruction of the whole world as unreasonable, mad, insane, they are really giving confused expression to this sense of disapprobation.

What’s registered by the moral experience of the vulgar, is the conflict between the calm and violent passions even though this has a tendency of being misconceived as the conflict between reason and the passions due to the phenomenological similarity of the operation of the calm passions and the operation of reason encouraged by a Stoic rhetoric entrenched in Western moral thinking.

The Combat of Duty and Inclination

In a civilized state, if not in a rude and natural state, a sense of duty can move a person to observe the demands of justice even it is not beneficial to himself or others and even if it is harmful to himself and others. The demands of duty seem to be quite independent of human inclination, that is, the contingent configuration of the human passions. The categorical demands of our sense of duty seem inconsistent with a sentimentalist account of them.

Hume’s strategy is again reconciliationist, he wants to allow that there is something that is registered by the moral experience of the vulgar and yet that they tend to misconceive this.

The key difference between the natural and artificial virtues is this: While the operation of the natural virtues invariably results in some good, the operation of the artificial virtues does not. Justice, for example, can demand a repayment of debt even if it is contrary to private and public utility. Public utility does not attach to particular observances of the rules of justice but to the general scheme or convention. These conventions are first established by man’s self interest and confined benevolence in conditions of scarcity where the relevant goods admit of easy exchange. Once set up, and society stabilizes and grows, the original motive to justice has a tendency to wane and the temptation to free ride increases. However, there arises a new motive to justice as we come to attach a kind of moral beauty to the observances of the rules of justice just because they are what justice requires. This pleasure we register in the observances of justice due to the operation of sympathy and the imagination is independent of whether the particular observance serves any antecedent end we may have.

What’s registered by the moral experience of the vulgar is the contrast between the natural and artificial virtues, that artificial virtues is independent of private and public utility and may even be contrary to private and public utility. Nevertheless Hume can explain why this is so by postulating the principle of sympathy at work in generating our moral sentiments.

Here, I must confess, that at least in one respect, Hume’s reconciliationist ambitions are frustrated. The domain of duty, the domain of the categorical, is conceived by Hume to be far more restrictive than the vulgar conceive it to be. According to Hume, the only duties to which we owe categorical allegiance are duties of property, allegiance to the state, promise-keeping, and chastity. This is are more restricted conception of duty than the one that the vulgar operate with. To take one prime example, Hume allows for no duties of aid. So Hume can capture the phenomenology of the conflict of duty and inclination but at the cost of restricting the range of duties there are, perhaps unduly so.

The Self Vindicatory Nature of the Sentimentalist Explanation of Morals

While Hume’s sentimentalism purports to explain the moral judgmenta that we make, given the character of that explanation, it also justifies or vindicates these moral judgments.

Explanation and Justification

Hume believes that once we understand fully the sentimentalist explanation of moral judgments, we will naturally approve of, not only these judgments, but also of our sense of morals and the principles that give rise to it:

All lovers of virtue (and such we all are in speculation, however we may degenerate in practice) must certainly be pleas’d to see moral distinctions deriv’d from so noble a source, which gives us a just notion both of the generosity and capacity of human nature. It requires but very little knowledge of human affairs to perceive, that a sense of morals is a principle inherent in the soul, and one of the most powerful that enters into the composition. But this sense must certainly acquire new force, when reflecting on itself, it approves of those principles, from whence it is deriv’d, and finds nothing but what is great and good in its rise and origin.

This Hume sees as a distinct advantage of his sentimentalism, grounded as it is in the operation of human sympathy, over the sentimentalism of his predecessor, Francis Hutcheson:

Those who resolve the sense of morals into original instincts of the human mind, may defend the cause of virtue with sufficient authority; but want the advantage, which those possess, who account for that sense by an extensive sympathy with mankind. According to their system, not only virtue must be approv’d of, but also the sense of virtue: And not only that sense, but also the principles, from whence it is deriv’d. So that nothing is presented on any side, but what is laudable and good.

Notice for something to have merit and to be the object of moral approbation just is for that thing to give rise to a distinctive kind of pleasure upon the general view or survey. If not only our moral judgments, but our sense of morals and the principles that give rise to them would please a Judicious Spectator, then these have merit and are the proper objects of moral approbation. Hume’s new science of human nature is primarily descriptive and explanatory in its ambitions, as opposed to prescriptive and justificatory. Moral science seeks to describe diverse phenomena of human psychology and activity and explain these in terms of a few general principles. Moral science does not seek to prescribe that we make certain moral judgments. He is not engaged in any casuistry, nor is he offering a moral sermon or panygeric to Virtue. He is not recommending moral judgments to his audience. hume takes it for granted that he agrees in large measure with the moral judgments of his audience. Nor does moral science seek to justify the moral judgments that we actually do make. Hume is not trying to justify the moral judgments we make. He is not trying to persuade a moral skeptic. Nevertheless once the explanation is set up and understood, we naturally approve of these principles and so perceive nothing that is not laudable and good. Hume’s sentimentalist explanation of morals purports to vindicate itself.

Self-Knowledge and Moral Transformation

The knowledge that a Humean moral scientist seeks is a kind of self-knowledge. The moral scientist seeks to explain the distinctions we make between vice and virtue in terms of our common human nature extended, where it is, by human convention. In learning about the few general principles that govern the diverse phenomena of human sentiment and that determine our judgments of vice and virtue, we learn about ourselves. We learn what kind of creatures we are.

While reason alone can neither determine the will nor oppose the passion’s determination of the will, the self-knowledge we gain from Hume’s moral science is not entirely indifferent to us. We come to naturally approve of our moral judgments and the principles that give rise to them. The human affective sensibility must be so configured, that the kind of self-knowledge afforded us by Hume’s science of human nature is naturally pleasing to us upon the general view or survey. Not only is this self-knowledge pleasing to the human sensibility, it helps to transform our moral character. In particular, this self-knowledge strengthens our virtuous character:

But this sense [sense of morals] must certainly acquire new force, when reflecting on itself, it approves of those principles, from whence it is deriv’d, and finds nothing but what is great and good in its rise and origin.

So in approving of the the principles that determines our moral sense, the moral sense acquires new force, it gains new strength. Strength is a matter of causal control. Thus the causal influence of our sense of moral would tend to increase once it reflects on and approves of the principles upon which it is founded. In the case of the artificial virtues, such as justice, this would be manifest in an increased ability of the sense of duty, the sense of the moral beauty of particular observances of the conventions of justice, to oppose other passions that might conflict with it, such as selfishness or even benevolence. The categorical nature of these demands would be strengthened.

Though Hume sets out to be an anatomist of morals rather than a painter of virtue, nevertheless, the kind of self-knowledge we gain from the science of human nature has a natural tendency to transform our moral character by strengthening the operation of our moral sense. In gaining this self-knowledge, our moral character is transformed. Like Socrates before him, Hume sees a connection between self-knowledge and human virtue.

The precise connection he sees is perhaps the finest expression of Humean optimism. Humean optimism is characterized by a realistic if cheerful appraisal of human nature. We are not utterly selfish, but neither are we angels. Even given this realistic and balanced conception of human motivation, Hume is pleased with what it gives rise to, the moral distinctions it makes and the principles that govern these. A fact that is, perhaps, echoed by the literary pleasure we take in the nature and character of the author of the Treatise.