What is Human Nature According to David Hume?

What kind of thing are we, most fundamentally? Many people would be tempted to answer that question by claiming that what they are, most fundamentally, is human beings. The question then raises itself: what is a human being, fundamentally? This is the question that motivates David Hume’s philosophy.

In particular, he hoped to apply a method analogous to that pursued in the natural sciences to the study of human beings. Yet, at the same time, his philosophy demonstrates that the study of human beings, like humans themselves, must be conceived of in an utterly singular way.

This article explores Hume’s theory of human nature, with reference to one of its most important modern interpretations – that which was offered by Gilles Deleuze in his first book, Empiricism and Subjectivity. It begins by explaining Hume’s, largely unfair, reputation in the history of philosophy. It then moves on to focus on how Hume wished to adapt the experimental method of science for his study of human nature. It concludes with an analysis of the role of passion and reason in human nature.

Hume’s philosophical reputation, at least in the English-speaking world, is a somewhat negative one. This has to do, in part, with how his work was originally situated in the history of philosophy.

Teleologically-minded 19th-century historians of philosophy (that is, those who see philosophy as having a necessary direction and destination) tended to place Hume as carrying the empiricist tradition to its natural conclusion and thereby laying the way for Kant and post-Kantian philosophers like Hegel.

However, this misunderstands both the positive content of Hume’s philosophy and its originality. The central motivation of Hume’s philosophy is to provide a theory of human nature. As Barry Stroud (another modern interpreter of Hume’s) puts it, his work constitutes an “expression of the unbounded optimism of the Englightenment…[the] outline of which… represents for many people the very paradigm of what it is to have an explanation of something”.

Hume’s first work of philosophy, in which many of his most important ideas are articulated, was A Treatise on Human Nature. The subtitle of this work reads: “An Attempt to Introduce the Experimental Method of Reasoning into Moral Subjects.” For Hume, ‘moral subjects’ aren’t just limited to questions of ethics, but any questions about human beings (as distinct from natural objects or processes). Hume is interested (indeed, singularly fixated) on asking what makes human beings special without prejudice or a priori assumption.

Scientific investigation is clearly set against the approach to human nature Hume finds in ancient philosophy and literature, which casts it in the most positive terms. It should be no surprise that one contemporary critique of Hume, which comes from Frances Hutcheson, was to the effect that Hume’s account of human beings lacked warmth, given that he was trying to do for human beings the thing that natural sciences had, on his account, already done for the rest of nature: “anatomize” it, and explain all of the various phenomena within it. The relevant features of a scientific theory that Hume was especially concerned with included the requirement that it be all-encompassing (it should leave no phenomenon out), and that it should rely on only a few, basic underlying principles. It is these principles Hume is after, and not a full account.

When he came back to make some amendments to the Treatise, Hume said:

Moreover, his ambition was to follow the method of science – what he calls the “experimental method.” The method should be based exclusively on “careful and exact experiments, and the observation of those particular effects, which result from its different circumstances and situations.” Hume is self-conscious about the limitations of applying an “experimental method” to human beings, calling for a “cautious observation of human life” on the grounds that one can’t easily manipulate the objects of experimentation.

Of course, as the history of the human sciences goes to show, manipulation of various kinds may actually be possible. In spite of this perceived limitation, Hume seems quite set against “invention” in the realm of human sciences, against “essences.” One thing which Gilles Deleuze attempted to show in his analysis of Hume was that essence, or at least something functionally similar, is reinserted into Hume’s philosophy subtly at different points. One such point is in Hume’s analysis of the passions (on which more will be said shortly) as universal.

Now, Hume’s focus on empiricism might seem to force the question of what he thinks he is doing. Surely, he should really be doing something more “empirical,” like psychology or sociology. Philosophy is necessarily a priori, involving the litigation of meanings, concepts, logical relations etc.

Two rejoinding questions present themselves. Firstly, is philosophy necessarily a priori? And secondly, is there a firm distinction to be drawn between the empirical and the a priori? Of course, these are open questions, but they should be sufficient to at least problematize this particular critique of Hume. The Humean focus on creating a science of human nature runs deep. He was especially struck by the power of Isaac Newton’s thought, and elements of Hume’s theory of ideas demonstrates this. For Hume, simple perceptions leave us with simple ideas, which in turn can be used to construct complex ideas. Why do we call certain ideas to mind?

Why are some ideas related to one another? Hume’s answer is that there are “principles of association,” which sound an awful lot like gravity:

Is this an analogy or something more literal? Perhaps it’s something even more fundamental than that, a claim about the way in which things in general relate to things in general, the idea that the empirical worldview relies on the existence of relations or forces which cannot themselves be observed to make sense of the coherence of things.

To return to an earlier point about Hume’s originality, it is worth noting that Hume himself really doesn’t seem to see himself as pushing any so-called “empiricist tradition” to any so-called “logical conclusion”: “My principles are also so remote from all the vulgar sentiments on the subject, that were they to take place, they would produce almost a total alteration in philosophy: and you know, revolutions of this kind are not easily brought about.”

What arguably makes Hume a brilliant, revolutionary thinker is how he adds to this picture of ideas, which are of a qualitative piece with impressions, in order to create a convincing picture of human thought overall. To do this, he takes a great deal of inspiration from Francis Hutcheson’s theory of aesthetics and ethics. To simplify greatly, Hutcheson believes that we are naturally disposed to make ethical or aesthetic judgments (such as they are) based not on anything rational as such, but based on feelings. We do not make inferences from features of beauty or goodness, but rather we infer from our feelings.

Hume’s theory involves a radical extension of Hutcheson’s conception of feeling into a far wider sphere of human existence – indeed, almost every cognitive and intellectual element of our lives turns out to be, at its root, an expression of feeling rather than reason.

For Deleuze, this idea is also at the heart of Hume’s theory of ideas – ideas are, in a certain sense, if not themselves passions then definitely passional (that is, they are in some sense directed by the passions, or interpreted by them). In any case, Hume holds that “belief is more properly an act of the sensitive, than of the cogitative part of our natures” (laicization of belief).

Rationality, on several definitions, seems to imply something intentional, whereas for Hume we arrive at our beliefs about the world due to a combination of our perceptions and the principles of human nature. We find ourselves thinking something just as we find ourselves noticing that something is red. The question then is how and why we come to believe the things we believe.

Hume’s treatment of reason extends to a critique of human freedom: “Reason is …the slave of the passions, and can never pretend to any other office than to serve and obey them”. This is blatantly the reversal of how reason is normally conceived of, wherein reason is associated with control, autonomy, the instigation of processes in an intentional way.

Hume’s isn’t just opposing a conventional conception of human beings as fundamentally rational animals. He is also taking a shot at his philosophical forebears: Descartes, for instance, who claims in his Meditations that there are “two general modes [of thinking], the one of which consists in perception, or in the operation of the understanding, and the other in volition, or the operation of the will”, and elsewhere in the Meditations claims that “the will is absolutely essential for our giving our assent to what we have in some manner perceived”. This view takes human beings out of the causal order of the universe, and offers us the possibility of freedom. Hume denies it.

There appear to be two things happening side by side: the analysis of human nature and deflation of the foundational claim of reason. Hume tends to begin by analyzing the supposed ‘foundation in reason’ for a certain belief, showing (or claiming to show) that there is none, and then moving on to a more positive analysis of the passions. Generally, this is not an argument founded on Hume having a better explanation, grounded in passion, to explain a certain phenomenon. It is an attack which comes in two separate movements, first the negative, then the positive.

This idea of “dual focus” in Hume is common even among the various different modern interpretations of his work. For Deleuze, the two things are passions, desires, and what is imminent (ideas also) on one side, against what is determined by the principles of association on the other. These principles gain their own transcendence – that is, our capacity to go beyond what is given directly in experience is affirmed not by reason, but by the various principles of association.

Hume’s work remains thought-provoking and challenging for modern philosophers, and interpretative disagreements are entirely reasonable. What is undeniable is that Hume’s positive, original thought deserves the greater attention it is gradually receiving.