Hume's treatment of the passions is largely neglected. Apart from a couple of famous sections in the Treatise concerning the sources of action, the subject matter has rarely excited interest.Footnote ¹ The result is that his philosophy has been perceived largely in terms of the distinct subject matters of Books 1 and 3 of the Treatise, and of the two corresponding Enquiries, thereby creating the common picture of Hume as a philosopher engaged in two main fields: epistemology and metaphysics on the one hand, and moral and political theory on the other. Needless to say, this has not helped perceptions of the overall point or unity of the philosophy in general, nor of the Treatise in particular. The problem is not aided by the fact that, when Treatise Book 2 has been given attention, commentators have struggled to render it interesting.

There are two main reasons for this state of affairs. The first is, quite simply, that Hume's account in the Treatise is not, even on its own terms, entirely successful. Bold theses are advanced about the nature of various major passions, but then complications set in, and complications of complications, such that the theory begins to look ad hoc – as Hume himself admits at one point. (T 2.2.9.11; cf. 2.1.3.7)Footnote ² So, when he came to revise this part of the Treatise, in A Dissertation on the Passions, first published in 1757, the bulk of these complications were simply left out. The result is a much shorter and simpler work, designed to bring out clearly the fundamental message. The second reason for Book 2's relative neglect is that, to the modern reader, Hume's intentions have remained largely opaque. This has meant that even the Dissertation has attracted little serious interest: the prevailing attitude is that it is dull.Footnote ³ Perhaps worse, when it spells out its central aim, in its closing paragraph, it may seem only to explain its own dullness. What he says there is this:

Hume's aim is, in other words, to explain the passions entirely in terms comparable to modern mechanical science. Of itself this is unremarkable, since it was a hallmark of the mechanical philosophy to explain the passions in this way. Descartes offers just such an account in The Passions of the Soul, and he was followed in this by many other – otherwise opposed – adherents of the new philosophy. Thus Malebranche, Hobbes, and Spinoza all offer accounts of the passions in which the regularity of their causes is emphasised. Spinoza, most notably, remarks that ‘the emotions of hatred, anger, envy, etc., considered in themselves, follow from the same necessity and virtue of Nature as do all other particular things. Consequently, they recognize certain causes by which they are understood.’ Hume's main concern is the same, although his Newtonian analogies with the laws of motion and optics contrast with Spinoza's geometric model, with its aim to treat emotions and actions ‘just as if the inquiry concerned lines, planes, or bodies’.Footnote ⁵

Unfortunately, for the modern reader this sort of enquiry has become so familiar that its distinctiveness is easily missed. So one reason why Hume's account seems dull is that its aims may seem too obvious to deserve the attention they are given. After all, the very discipline of modern psychology is characterised by this causal approach to human behaviour. To recognize this is, however, precisely to recognize one major purpose of Hume's account: to offer his own version of the widespread intellectual ambition to replace the ancient and medieval picture of the human body and its relationship to the human mind with a new picture inspired by the new mechanical science. In fact, according to Descartes, one indicator of the superiority of the modern philosophy over the ancient is its very ability to offer an account of the passions. In his ground-breaking treatment of the subject, The Passions of the Soul, he writes that ‘the teachings of the ancients about the passions are so meagre and for the most part so implausible that I cannot hope to approach the truth except by departing from the paths they have followed’.Footnote ⁶ In effect, then, he marked out a new sub-discipline of philosophy, and rendered an account of the passions a necessary component of any philosophy inspired by the new science. This means that, by offering a causal account of the passions, Hume is responding to this implicit challenge; and, in so responding, he is, among other things, affirming his modernity.

Early Modern Passions: Physiology and Psychology

For modern philosophers – of all stripes – the passions were understood to be the mental effects of bodily motions. Thus Descartes observes that, although most perceptions caused by the body depend on the nerves, others do not. These others are distinctive in that

The passions thus have a bodily origin, differing from the sensations by the indirect manner in which they impinge on the brain, and therefore the mind. (‘Animal spirits’ means the early modern equivalent of nerve impulses: a rarefied fluid supposed to travel along the nerves to communicate between the body and the brain.) This also means that they are firmly related to the imagination, since he had already explained that faculty in terms of bodily processes impacting on the mind.Footnote ⁸ Descartes spells all this out by classing the passions as a species of ‘imaginings’, differing from sensations in that ‘their cause is not so conspicuous and determinate as that of the perceptions which the soul receives by means of the nerves, and they seem to be mere shadows and pictures of these perceptions’.Footnote ⁹

To this point, the dogmatic materialist Hobbes could agree with all that Descartes has said. In these respects, there is no specifically materialist account of the passions. The crucial point of disagreement concerns what happens after the animal spirits bring about events in the brain. Descartes, with his dualism of mind and body, can allow that the passions arise in the mind because of material motions in the brain, but he must deny that the mind is in any way constituted by those brain events. Rather, the mind, upon receiving this information – which is to say, upon feeling the feeling – must be free to judge the meaning of the feeling, and what to do about it. This is just what he does: he insists that the mind or soul is independent of the passions, and so can exercise control over them.Footnote ¹⁰ This is the litmus test for distinguishing between dualist and materialist theories: the dualist must affirm that the mind is capable of independence from the passions, and will typically hold that the mind can exercise control over them.Footnote ¹¹ In this sense, the dualist will affirm that the human being is rational and free. The materialist, in contrast, can be expected to resist any separation and independence of the mind from those processes which occur in it because of motions in the brain and body: thought, volition and passion should all occur on the same level, such that no part of the mind – in particular, no rational part – can claim to rule over the rest.

This is precisely what we find in Hobbes. He denies the very possibility of control over the passions by denying any space for reason or volition that is independent of passion: instead, he defines volitions by reference to the passions themselves. He proclaims this view in the very chapter title in which he treats of the subject: ‘Of the Interiour Beginnings of Voluntary Motions, Commonly Called the Passions …’Footnote ¹² He also treats the passions as a species of imagination: just as ‘sense is motion in the organs and interior parts of man's body’, so ‘it is evident that the imagination is the first internal beginning of all voluntary motion’.Footnote ¹³

This commits Hobbes to determinism. His view, which he develops in the opening chapters of The Elements of Law and Leviathan, is that the external world impinges on the human body, setting up motions within it. Some of those motions are passions; and passions – which are divisible into desires and aversionsFootnote ¹⁴ – are all there are to volitions. In fact, he adds, what we call the will is nothing more than the (obscure) awareness of the resolution of this whole process: it is simply ‘the last appetite or aversion immediately adhering to the action’. But how can passions be voluntary, if they are motions caused by other motions? Hobbes's answer is that there is no incompatibility between voluntariness and causation. The supposition that the two are incompatible is because of the mistaken view that the will is a separate faculty. There is, he says, no such thing: the will – willing – is an act, not a faculty. A willed act and a voluntary act are thus the same thing: ‘a voluntary act is that which proceedeth from the will, and no other’; and the ‘will’ is simply ‘the last appetite in deliberating’.Footnote ¹⁵ The message is repeated (and expanded on) when Hobbes comes to treat of the liberty of subjects. He says there that

This view provoked strong reactions, not least from the religious establishment, so Hobbes later found himself in an extended dispute with Bishop Bramhall about the nature of liberty and necessity.Footnote ¹⁷ This was no accident: to argue for the compatibility of liberty and necessity was to challenge orthodox positions on the freedom of the will, and therefore positions on the vital questions of human, and also divine, responsibility for evil.

How does reason fit into this picture? Hobbes rejects any special relationship between reason and volition. He argues that ‘the definition of the will commonly given in the schools, that it is a rational appetite, is not good’. It is at this point that he offers his definition of the will as nothing more than the last appetite in deliberating. But the objection applies not only to volition, but also to reason. The problem with the scholastic definition is not only that it supposes the will to be rational, but also that it supposes reason to be capable of directing action. Thus Hobbes claims that the very idea of a rational appetite – a rational desire or aversion – can hardly make sense, since, he says, reason, ‘when we reckon it amongst the faculties of the mind … is nothing but reckoning (that is, adding and subtracting) of the consequences of general names’. Reason is just the calculation of consequences or implications. This means, among other things, that reason cannot be practical: it cannot be an independent source of motives for action. Those motives must, then, derive from those voluntary motions that are the passions: reason must serve the basic passions of desire and aversion. Hobbes affirms the point with a military metaphor: ‘the thoughts are to the desires as scouts and spies, to range abroad and find the way to the things desired’.Footnote ¹⁸

The final element in this compound is Hobbes's hedonistic account of practical judgment and motivation. Since it is non-rational passion or desire that motivates, the motive force must equally be non-rational. It must also lie within the nexus of physical causes. Pleasure and pain are the only obvious candidates to play this role, and Hobbes does not hesitate to appeal to them. Thus he defines goodness as the object of desire, and pleasure as the appearance of goodness.Footnote ¹⁹ There is no free will to stand outside the physical processes and judge them: human beings are moved by pleasures and pains only.

Hobbes's picture is, then, as follows. The human being is a machine, set into motion by external impulses which set up internal motions within it. These motions include what we call thoughts and feelings. In so far as they are thoughts, they belong to the imagination. In so far as they are feelings, they are passions, and these are the beginnings of what we call voluntary acts. Such acts are, however, caused – the will is not a separate power (a separate faculty), but is just the last desire we feel in that chain of inner motions which lead to outer motions, that is, to actions. There is thus no such thing as free will. The will is also not a rational power, since reason is simply the ability, grounded in past experience, to calculate the pluses and minuses of alternative desired possibilities. It is not the ruler of desire or passion – it is its servant. Human beings are moved by pleasures and pains.

Hobbes thus offers an account of the relation between reason, will, imagination and passion that is wedded to his materialism. This account is explicitly materialist by explaining all psychological phenomena by reference to physiological causes. But it also shows how a theory could be implicitly materialist: by avoiding the physiology, but affirming the conjunction of doctrines about reason, will, imagination and passion that is distinctive of the Hobbesian theory. Hume's theory does just this. It does its best to avoid appeal to physiology, but in the other key respects, it fits the Hobbesian psychological template.

Hume's Hobbesian Psychology

There is no doubt that, throughout the Treatise, Hume does his best to avoid appeal to physiological explanations, but this should not be misconstrued: to avoid physiology is not to deny it. In fact, he shows himself prepared to appeal to it when it seems necessary. Thus, for example, in Book 1 he appeals to brain physiology to explain how errors in reasoning can occur. (T 1.2.5.20) He adds in that same paragraph that the reason why he has not made more use of physiology in developing his case is not ‘for want of something specious and plausible, which I might have display'd on that subject’, but because of the limitations built into his project: ‘’twas more in prosecution of my first maxim, that we must in the end rest contented with experience’. In other words, he avoids physiology wherever possible, first, because his project is psychological, and, secondly, because to introduce physiological claims will go beyond experience, and so import a degree of conjecture – however ‘specious and plausible’ – into the theory.Footnote ²⁰

The same outlook is evidenced at the very beginning of Book 2. In introducing the subject of the passions, he shows himself prepared to appeal to physiology. He says:

Here we see sensations explained by reference to the body: sensations arise either by physical contact with the external world or as a result of the body's own inner motions, including those of the ‘animal spirits’ (or, as we would say, the nervous impulses). These two causes are not, of course, mutually exclusive. The point is simply that the reflective impressions, or passions, are internal knock-on effects of any of these different kinds of bodily occurrence. If, however, Hume is prepared to accept some kind of physiological account of the passions, why does he not spell out his preferred view? His answer is the same as the one he has already given: the latter subject is wide of his purpose. He observes that the mind's perceptions ‘must begin somewhere’, but he will not investigate those origins because ‘these depend upon natural and physical causes, the examination of which wou'd lead me too far from my present subject, into the sciences of anatomy and natural philosophy’. He will instead limit himself to ‘those other impressions … call'd secondary and reflective, as arising from the original impressions, or from their ideas’. (T 2.1.1.2)

In short, Hume's interest is in the passions rather than sensations as such; and it is so because his enquiry is psychological – an investigation of ‘moral subjects’, as his title-page puts it – rather than physiological. But not only is he prepared to enlist physiology to his cause, where necessary; the psychological account he offers is entirely parallel to Hobbes's overtly materialist account. All the key doctrines of Hobbes's materialism – on the nature of the will, the relation of liberty and determinism, and the relation of reason to passion – are affirmed in Hume's theory.

First, Hume's definition of the will could have been written by Hobbes himself. He says: ‘by the will, I mean nothing but the internal impression we feel and are conscious of, when we knowingly give rise to any new motion of our body, or new perception of our mind’. This is not the most felicitous of phrasings – presumably he means that the feeling in question is the feeling of knowingly giving rise to motions – but the general thrust is clear: what we call the will is simply the feeling that attends the origination of the action, whether mental or physical. He complicates the picture a little by adding that, ‘properly speaking’, the will is ‘not comprehended among the passions’, being included only for the sake of a ‘full understanding’. (T 2.3.1.2) On this definition, however, it is not immediately obvious why not; after all, like the passions, it is an internal impression.Footnote ²¹ The important point, however, is that this account of one of the most fundamental concepts in the psychology of action is so startlingly brief because it is pure Hobbism. It could hardly be closer to Hobbes's identification of the will with ‘the last appetite or aversion immediately adhering to the action’; and, like Hobbes's view, it is implicitly determinist by making the will nothing more than an experience that attends, or is part of, a chain of causes and effects.

That this is also Hume's point is shown by the fact that this account of the will occurs in the introductory paragraph of the sections devoted to arguing for the second of the three Hobbesian doctrines: the truth of determinism, and its compatibility with liberty. (T 2.3.1–2) That argument is too well known to need detailed exposition. It is sufficient to note resemblances and differences. The resembling feature is that Hume's argument, like Hobbes's, reduces freedom to the power to choose. The difference is that Hume avoids Hobbes's dogmatic necessitarianism about nature, replacing it with his account of what nature's regularities force us to believe. For present purposes, however, the important point is that the purpose of Hume's compatibility argument is not to weaken the case for determinism, but to remove an objection to it. His definition of the will immediately denies the possibility of free will in the traditional sense of a power independent of normal causal processes, and thereby reduces the meaning of ‘freedom’ to the power to choose. This power is a manifest quality, and so is affirmed by the fact that we do exercise choice; its compatibility with determinism is established by the further fact that the choices we make display the same regularity on which ordinary causal judgments are based. Thus the appeal to human freedom does not undermine a determinist theory of human nature, since, Hume argues, properly understood, neither the will nor the power to choose constitute obstacles to that theory. In affirming these two aspects of Hobbes's determinism, Hume thereby endorses doctrines that are key elements of Hobbes's materialist account of the human being.

The third and final aspect of Hobbes's materialism is his subordination of reason to passion, and on this doctrine as well Hume follows suit. Indeed, his famous claim, 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’ (T 2.3.3.4), is simply a rephrasing of Hobbes's claim that reason is the ‘scout’ of the passions or desires. Moreover, the arguments he offers for this conclusion reflect the Hobbesian view that the role of reason is merely calculation.

Thus he argues, first, that reason, where it concerns relations of ideas, has no direct bearing on action. Its influence is indirect, in that rational calculation is an important servant of independently-given ends: ‘Mathematics … are useful in all mechanical operations, and arithmetic in almost every art and profession: But ‘tis not of themselves they have any influence. Mechanics are the art of regulating the motions of bodies to some design'd end or purpose.’ (T 2.3.3.2) That is, calculations are useful because they provide accurate answers to questions that arise, not from them, but from the purposes of the human beings who employ them. Human beings have purposes, and they employ abstract reasoning to pursue those purposes more accurately and effectively.

The same model is applicable to reasoning from experience. Hume falls into line with Hobbes's hedonism by accepting that human purposes begin from the prospect of pleasure or pain: ‘’Tis obvious, that when we have the prospect of pain or pleasure from any object, we feel a consequent emotion of aversion or propensity, and are carry'd to avoid or embrace what will give us this uneasiness and satisfaction.’ But, he adds, in caring about the end, we also have to care about the means to its achievement. The emotion naturally leads us to a consideration of relevant causes and effects, and it is at this point that reason enters the picture: ‘Here then reasoning takes place to discover this relation; and according as our reasoning varies, our actions receive a subsequent variation.’ However, despite bringing about this variation in the action, it is a mistake to think that reason is a force that of itself changes the direction of the action. The force comes from the pleasure or pain that is the source of the attraction or aversion: ‘But ’tis evident in this case, that the impulse comes not from reason, but is only directed by it. ’Tis from the prospect of pain or pleasure that the aversion or propensity arises towards any object.’ (T 2.3.3.3; emphasis added)

Hume's language here brings out the background mechanical picture: actions are the result of aversions and propensities, which are impulses. An impulse is a force applied by direct contact, and so impulse is the sine qua non of mechanical causation: as Locke puts it, impulse is ‘the only way we can conceive Bodies operate in’.Footnote ²² Hume does not often appeal to this idea – although the importance he attaches to contiguity as a marker for causal connections is evidence of its influence on his theory of causal belief – so it is striking that he does so here, where what is at stake is precisely just what it is that provides the motivating force of action. However, it is in the further implication he extracts from this thesis – that reason, if not the cause of actions or propensities, is neither capable of opposing them – that the language of ‘impulse’ becomes ubiquitous:

This passage is particularly striking because Hume could have avoided much of the ‘impulse’ talk to make his main point: that reason, if unable to influence the will, cannot oppose it either. In other words, most of the work of the argument is done by his restrictive conception of reason – as either demonstrative or probable – on which he has based the conclusion that reason cannot influence the will. The further conclusion, that reason cannot oppose the will, seems little more than a corollary. But to persuade the reader of its truth, he employs language so characteristic of mechanical physics that his adherence to a mechanical theory of human mind and action becomes undeniable. The salience of the mechanical model at this point thus puts in proper context the famous conclusion to which these arguments lead:

The subordination of reason to passion is, then, not only an argument about the inefficacy of reason, but also an argument grounded in the impulsive power of the passions. The passions are, in other words, not merely impressions – feelings – but mechanical forces. This is a conjunction that falls into place against a background of mechanical physiology: passions are feelings, but they are feelings because they are internal motions in a material being. Passion can produce action because it is bodily motion, and bodily motion brought into contact with other bodily parts imparts an impulse to those parts. Moreover, passion also produces volition because volition is simply the feeling of such an impulse. There is no faculty of will outside these bodily motions. And, finally, reason is not the source of any impulse (or counter-impulse) because it, too, is simply another component of these motions. On Hume's account, there is nothing outside the impulses of the passions, and so nothing capable of opposing them. There is only the system of mechanical interactions between a body and a world. Thus Hume's subordination of reason to passion, and his related incorporation of volition into the same overall account, commits him to determinism, and, implicitly, to materialism.Footnote ²³

Finally, on this account, internal conflict can only be between different impulses, and so between different passions. What then of those conflicts that are commonly supposed to be between reason and passion? Hume's answer is that this common supposition depends on confusing reason with something different but resembling. In its ordinary employments – that is, outside ‘the more sublime disquisitions of philosophy, or in the frivolous subtilities of the schools’ – reason is a calm or mild action of the mind. This fact, Hume claims, has led to the error of supposing that all such calm actions are due to reason:

It is, then, these calm passions, not reason, that explain our basic orientation as human beings. And, since it is these calm passions that are mistakenly identified as reason, it means that, when moralists talk of the conflict between reason and passion, the conflict is actually between these calm passions and other, violent or strongly-felt, passions. Hume's subordination of reason to passion is not, then, the claim that we are ruled by strongly-felt passions. Reason serves both kinds alike; and, given that it is the calm passions that constitute the default setting of the human being, the activity of reason is typically at the service of the calm rather than the violent passions. It is this alliance of obedient reason with calm passion that is the condition normally called rational, and with which violent passions often contend. Internal conflict is real; but that combat is not in fact between reason and passion, but between calm passions and violent opposing passions.

Hume thus offers a consistent account of the human psyche. However, the important moral, for present purposes, is that his account of calm passions again implies a background physiology. As he says, they are ‘real passions’, even though they ‘produce little emotion in the mind, and are more known by their effects than by the immediate feeling or sensation’. In other words, calm passions are not necessarily impressions at all. In what sense, then, are they passions? The answer is that they are passions because they have effects, that is, they are causes of motions. Here we see, then, the concept of a passion shifting from its psychological meaning – being an impression or feeling – to its mechanical physiological meaning – being an impulse which is a cause of volition and action. In the case of the violent passions, these two meanings are co-extensive; in the case of the calm passions, in contrast, the impression may be undetectable, but the terminology is still appropriate because the underlying physiological picture is unchanged. Hume's doctrine of calm passion is, then, the final brick in the wall for an account of human psychology fully in accord with mechanical materialism.

Passion, Action and Mechanism

One last piece of evidence for this conclusion is to be found in the otherwise thoroughly paradoxical nature of the theory, shared by Hobbes and Hume, that the cause of human action is passion. It has already been observed that the theory of the passions is a preoccupation of self-consciously modern theories. It has also been shown that, for Hume, a passion is an impulse, and in certain cases need not even be a feeling. These elements fall into place when it is recognized that, in the modern theory stemming from Descartes, what makes a passion a passion is its manner of origin. That a passion is felt is a datum, but the passions are so called because they are phenomena that are understood to arise in the person passively. A passion is something that happens to the person, not something that he or she does: a passion is the opposite of an action. Thus Descartes says that ‘whatever takes place or occurs is generally called by philosophers a “passion” with regard to the subject to which it happens and an “action” with regard to that which makes it happen’.Footnote ²⁴

This immediately reveals the paradoxical nature of the view that passions are the causes of actions: it is the view that human activity is caused by human passivity. This seems a contradiction in terms; but the explanation lies in mechanical theory. The paradox is discovered to be merely apparent by recognizing that the theory is simply the consequence of adopting a mechanical, and so deterministic, model of human nature. To say that human activity or action is caused by human passivity or passion is to say that human beings are not the originators of their actions. They are not the originators because those actions are themselves caused, and caused by motions which are passive because they are themselves caused. And so on. The larger picture becomes clear if we return to the Hobbesian physiological account: the external world impinges on the human body, setting up motions within it, motions which are the source of human actions. Those motions in the body are passions, because they arise passively: they are effects of external causes. What we call the will is just a part of – the last link in – this whole chain of mechanically-induced motions: it is simply the (obscure) awareness of the resolution of the process in actions. To hold, then, that human beings are not ruled by reason because reason is a slave to passion is to reduce the human mind to a mechanism whose motions are the result of external motions applied to it. The moral is, quite simply, that the human being is a machine, fully determined by the forces that act upon it.

To sum up: Hobbes's psychology is overtly materialist, being explicitly backed by a mechanical physiology. Hume makes no such explicitly materialist avowals, but in all relevant respects his account maps onto Hobbes's. He avoids physiology where he can, but nonetheless appeals to it when it suits him. He denies that there is a faculty of the will, reducing the will to an impression that accompanies action. He reduces freedom to a deterministic theory of choice, and so endorses compatibilism.Footnote ²⁵ This amounts to the abolition of metaphysical free will. He subordinates reason to passion, and treats the latter as an impulse. Finally, he adopts a theory of calm passion, in which the idea of a passion is equated not with feeling but with a cause of action. Taken together, then, these elements comprise a mutually-supporting network of theses corresponding almost exactly to the Hobbesian account of the human being as a machine. It is not credible to suppose that these resemblances are accidental, or that Hume did not see their significance. To hold, then, that Hume's account of the passions is implicitly materialist is simply to affirm that he knew what he was doing.

Materialism and Religious Critique

Hume's implicitly materialist account of the human psyche is not intrinsically anti-religious, since much Christian thought has been mortalist, emphasising the divine resurrection of the body rather than the possession of an immaterial and so immortal soul.Footnote ²⁶ However, as the example of Hobbes and Bramhall shows, it inevitably put him at odds with contemporary religious orthodoxy. That orthodoxy typically affirmed both the immateriality of the soul, and two attendant doctrines: the necessity for reason to rule over passion, and the reality of free will. Moreover, the orthodoxy went one step further – a step which inevitably raised the temperature in any disagreement. It claimed that moral virtue and moral responsibility rest on these twin pillars. Thus Samuel Clarke – whose Boyle Lectures of 1704 had made him a recognized champion of orthodoxyFootnote ²⁷ – insisted that moral virtue depends on rational mastery of the passions. In one of his published sermons, he says that virtue depends on

Notice that it is ungoverned passion that is the threat to ‘the Law of the Mind’. The passions themselves are not intrinsically bad – but they are intrinsically problematic. They cannot govern themselves, and, left to themselves, inevitably lead us astray. This viewpoint is elegantly expressed in a musical work of the period, William Hayes’ The Passions, which first appeared in 1750. The libretto, by the Oxford poet William Collins, allows each passion to speak for itself before reason is introduced to spell out the basic problem:

Plainly, the passions do not know their place, and this is their fundamental flaw. It is only by being brought under the sway of reason that harmony can be achieved. Thus, after reason has spelt out the cure, the chorus chimes in with the work's overarching moral:

The rule of reason is, then, on this orthodox picture, the key to the proper expression of the passions, and so the means by which the disorder and vice they threaten is avoided.

With its specific focus on the modern concept of passion, this is a modern view; but its roots extend all the way back to Plato and Aristotle. Thus Plato argues in the Republic that the harmonious and just soul is the soul ruled by reason, since only by such rule can the spirited and appetitive elements of the person be kept in their proper place.Footnote ³⁰ Aristotle's doctrine of the ‘mean’ has a similar point. It is only through reason's government that our non-rational character traits can express themselves in the right way, and so conform to virtue rather than vice. Thus courage is good because, governed by reason, it is the appropriate response to fear; cowardice and foolhardiness are, in contrast, ungoverned, and are vices – of deficiency and excess, respectively.Footnote ³¹ These views, ancient and modern, are thus united by the common conviction that the passions, although not naturally evil, are naturally unruly, and so, if left ungoverned by reason, will lead us into vice. This means that rule by passion is synonymous with vice; the passions were thus regarded with considerable suspicion, as ever-present threats to the leading of a virtuous life.Footnote ³² And, given that self-appointed guardians of public virtue are not always inclined to respect subtle distinctions, the finger was often pointed at the passions as if intrinsically evil.

It is this cluster of ideas that Hume decisively rejects. By subordinating reason to passion, he denies the possibility of rational government of the passions, and by claiming that that subordination is as it ought to be, he even rejects the desirability of such government: the passions are not, and ought not to be, governed by reason. They are inevitable – and in this sense natural – products of the normal workings of the human being. They may of course be dangerous, but reason is not the cure: it is not a higher faculty capable of ordering any other faculty, and so cannot do the job. So Hume's point is not to reject the ideal of the virtuous life, but to offer a new account of how such a life is possible. It is obvious that human beings do regulate their behaviour in various ways, including seeking to calm or otherwise neutralise their tendency to violent passions, so it must be that there is some means by which this is done. Hume's theory implies that it must be the passions themselves that regulate the violent passions. And, since the priority of passion in explaining action is an implicitly mechanical and deterministic model of the human being, Hume's theory amounts to the view that the human being is a kind of self-regulating machine.

This implies, among other things, a re-evaluation of the moral significance of the passions. Although Hume's view can allow that some passions are threats to a virtuous life, it is not because they are passions that they constitute such a threat. Passions, understood as the felt inner motions by which human beings are moved to action, the necessary consequences of causal processes occurring in the human body, must be, considered purely as inner mechanisms, entirely neutral. Necessary natural processes cannot be understood to be intrinsically good or bad.

This was certainly the conclusion drawn by Spinoza, whose own theory of the passions is cast in a mould very similar to those of Hobbes and Hume. He says this:

Spinoza is thus offering a natural-scientific investigation of the causes of the passions; he is also, like many modern advocates of the same approach, treating it as a factual enquiry entirely separate from value questions. The quotation also brings out clearly just what he, and by extension his intellectual fellow-travellers, saw as the opposition: the (typically dualist) conception of the human being as properly governed by reason, and of the passions as naturally anarchic forces that threaten to disrupt reason's legitimate rule, such that the good life depends, first and foremost, on subduing or destroying them. The modus operandi of this alternative view is thus criticism of the passions, together with exhortation to control them. In its religious form it produces, above all, religious moralizing.

Against this background, both the resemblances and the differences between Hume and Spinoza stand out. On the one hand, despite the contrast between Spinoza's geometric analogy and Hume's Newtonian appeal to ‘the laws of motion, optics, hydrostatics, or any part of natural philosophy’, their accounts of the passions are two of a kind: attempts at a scientific account of the causes of the passions, such that moralizing about the allegedly intrinsically harmful nature of the passions is shown to be confused. On the other hand, Hume's hedonistic account of desire and aversion means that the passions will be judged virtuous or vicious according to their felt qualities. This leads him into evaluations of particular passions often sharply at odds with the religious moralists.

Pride and Humility, Love and Hatred

The implicit critique of religious moralizing is evident in Hume's very choice of the passions to analyse – pride and humility, and love and hatred – because these are passions that carry significant moral freight, especially for Christian moralists. To begin with pride and humility. Especially in the Protestant world, influenced by Lutheran and Calvinist theologies, the orthodox view was that pride was the besetting sin of human nature, and so intrinsically evil, whereas humility was the Christian virtue, and so most to be admired. To get an idea of the kind of invective that pride attracted, consider the following passage from Richard Allestree's widely-read devotional and moral tract, The Whole Duty of Man:

For Allestree, then, pride is a common feature of human psychology, but it is always a failing: to fall under its influence is to be foolish, petty or vain. This was no minority view. In its day The Whole Duty of Man was a much-admired work. Originally published in 1658, it reappeared in a new edition in 1735, and, as Boswell shows in his Life of Johnson, it was still attracting high praise in the 1770s.Footnote ³⁵ Most importantly, Hume himself read it when young. He told Boswell, not long before his death, that he had been religious when young, and that ‘he used to read The Whole Duty of Man: that he made an abstract from the catalogue of vices at the end of it, and examined himself by this’.Footnote ³⁶ The evidence of the Treatise is that he did not forget these lessons: to see this, it is only necessary to compare the varieties of pride that Allestree denounces with Hume's account of the same passion. Whereas Allestree denounces pride in mental and physical endowments, in moral qualities, in wealth and titles, in the high estimation of others, Hume treats all of these topics in succession, treating them as natural tendencies free of any moral or intellectual taint – as, indeed, justified responses to pleasing experiences. (T 2.1.7–11) In other words, Hume's selection of topics in his treatment of pride and humility is most plausibly regarded as reflecting the desire directly to counter Allestree's attack on pride as a vice of foolishness and vanity.

This possibility is reinforced by the fact that the foundation-stone of Hume's account, the ‘double relation of ideas and impressions’ (T 2.1.5.5), seems designed precisely to rule out the possibility of regarding pride as intrinsically vicious (and, correspondingly, of humility as intrinsically virtuous). Not only does this account make feelings of pride or humility natural responses beyond our control, the hedonistic conception of motivation on which it relies reverses the traditional moral judgments. By analysing pride as (innocently) pleasurable and humility as painful, it renders the former naturally attractive and the latter naturally repulsive. The implication is that we cannot but judge pride as good, humility as evil. It is not, then, due to the corruption of our nature that we are inclined to pride, but because of a natural and necessary causal process by which, unless ourselves corrupted by bad metaphysics, we cannot but judge.

Hume develops this point in Book 3, when he turns to consider the case of the great man. The significance of this case for his overall view is difficult to exaggerate. It is considered directly in Treatise 3.3.2, but is in the background in the three subsequent sections, in his comments on anger (T 3.3.3.7–9), importance (T 3.3.4.14), and the goods of fortune (T 3.3.5.5).Footnote ³⁷ The case is significant because it shows the value of due pride: the great man takes pride in himself and his achievements, and, Hume claims, we accept that this is his due; that due pride is justified pride. He illustrates the point with a quotation from Alexander the Great, in which that man berates his companions for threatening to leave him, since this means missing out on sharing in the glory that awaits him. (T 3.3.2.12) Hume's point is that we accept such pride because it is firmly grounded; we do not reject it, despite its obvious lack of humility. He immediately points out that this conclusion is directly at odds with religious moral values:

Hume thus makes it plain that he sees himself, in his treatment of pride, to be advocating classical values rejected by Christian moralists. In fact, these latter sections of the Treatise in particular show Hume to be true to the claim he had made to Francis Hutcheson: ‘Upon the whole, I desire to take my Catalogue of Virtues from Cicero's Offices, not from the Whole Duty of Man. I had, indeed, the former Book in my Eye in all my Reasonings.’Footnote ³⁸ Hume's psychology of pride underpins Ciceronian, not Christian, values.

The anti-Christian message also emerges in Hume's treatment of love and hatred, if less directly. Love and hatred, like pride and humility, arise necessarily as a result of the double relation of impressions and ideas. The difference is that that they are directed at others instead of oneself. The former arises because of pleasing perceptions and must be judged good; the latter because of painful perceptions, and must be judged evil. (T 2.2.1) This is not, of itself, to deviate from Christian morals – but Hume's larger picture turns these apparently innocent judgments into a rejection of all strict moralizing. The key element is the hedonism: whatever pleases us we love, and whatever causes us pain we hate. But moral judgment itself reflects this division: whatever pleases us in another – when we judge from an impartial point of view – we denominate virtuous, whatever causes pain in like manner we denominate vicious. This means that moral approval is a form of love, whereas moral disapproval is a form of hatred. As Hume says, praise or blame ‘is nothing but a fainter and more imperceptible form of love or hatred’. (T 3.3.5.1; cf. 3.3.1.31) It can now be seen how this account diverges sharply from Christian (and, indeed, all strict) moralizing: the strict moralist is a creature of hatreds. Of course, even this could be squared with Christian morals were it not for Hume's insistence that moral judgment is not of actions per se, but of character, of durable mental principles which ‘enter into personal character’. (T 3.3.1.4) Were it not for this last element, Hume's theory would allow the Christian view that it is right to hate the sin but not the sinner; but if, as on his account, moral disapproval is directed at durable qualities which ‘enter into personal character’, then moral disapproval is a species of hatred of the very person.

Hume's accounts of specific passions are not, then, merely disinterested analyses of types of psychological responses. As in the general case, so in the particular: the moral is that the popular religious moralists are wrong; that a psychology uncorrupted by bad metaphysics turns the popular morality of religious orthodoxy on its head. (T 3.3.4.4)