I.

Introduction

Thomas Hobbes (1588-1679), English philosopher, scientist, poet, historian, and literary critic. One of the most influential of those thinkers who suppose that our obligations to obey governments depend on a social contract. In Hobbes’s contract we trade obedience for security. He is associated in moral philosophy with egoism—the doctrine that what is right is what is in our self-interest; and in metaphysics with materialism—only matter is real—and determinism—our actions are the inevitable products of impersonal causes.

II.

Life

Born in Malmesbury, Wiltshire, on April 5, 1588, Hobbes was the son of a vicar who left his parish and his family in disgrace when Hobbes was a child. Helped by his uncle to continue to Oxford after his schooling, he worked for most of his life for the wealthy and influential Cavendish family, the dukes of Devonshire. For about 20 years from 1608, he served as tutor and companion for successive generations of male heirs to the Devonshire title. This involved him in guiding travel to the Continent—part of the upbringing of the English nobility. Hobbes also acted as business agent, counsellor, and resident intellectual and translator for the Cavendishes. He was enlisted to help them in their political projects, getting involved on the king’s side in the disputes between Charles I and Parliament over raising money for military action.

From 1640 to 1650 Hobbes lived in Paris, fleeing there in anticipation of the English Civil War. The Cavendishes had Royalist sympathies, and Hobbes had written material for Royalist parliamentarians. His years in Paris were philosophically and scientifically productive. He returned to London in 1651, while England was still under the government of Oliver Cromwell, and eventually rejoined the household of the Cavendish family. The Restoration of Charles II, whom Hobbes had served as mathematical tutor in Paris, did not greatly improve his fortunes. Suspected of atheism and accused of heresy, notorious and famous as the author of Leviathan, involved in ill-tempered disputes with a host of intellectual opponents, he was prevented from publishing on controversial subjects. He eventually withdrew from political and scientific debate but remained active as a writer and translator until shortly before he died, in December 1679.

III.

Writings

Hobbes’s most productive period of thinking and writing probably comprises the two decades from the mid-1630s to the mid-1650s. During this time he developed the moral and political philosophy for which he is still celebrated, as well as the theories in natural science that he claimed particular credit for. In the same two decades Hobbes worked on a three-volume work that expounded the main sciences on the basis of a small number of “elements” or fundamental concepts.

A.

Moral and Political Philosophy

Hobbes stated his moral and political philosophy not once, but three times. The best-known formulation of his ideas today is that of Leviathan, written at the end of his time in Paris and published in London in 1651. This book was probably not Hobbes’s preferred version of his moral and political philosophy. For one thing, Leviathan is not about moral and political obligations simply, but about the implications of moral and political obligations for religious believers and for such institutions as churches. The message of Leviathan is that churches have no authority that is not given them by governments, and that they cannot presume to override or get round the authority of governments by telling ordinary members of churches that their supposed obligations to God conflict with and take precedence over the laws governments impose. Leviathan was directed against the claimed authority not only of the Pope, but of the Protestant bishops as well. Hobbes also used Leviathan to show that the Bible did not conflict with the need to obey governments.

Two other works of moral and political philosophy by Hobbes predate Leviathan and have less to say about relations between Church and State. These are The Elements of Law (1640) and De cive (On the Citizen), which appeared originally in Paris in 1642. Only the second of these two books was actually published by Hobbes. The first was written as a kind of briefing document for Royalist parliamentarians, supplying them with arguments from first principles for cooperation by Parliament and citizens with the king in matters of national security (including the raising of finance). These arguments were particularly topical, in view of the many years of difficulty Charles I had had in winning parliamentary approval for military and especially naval expenditure. From about the middle of the 1620s, a whole series of conflicts between king and Parliament had broken out about the means used by the king to raise money and also to organize and house troops for various military ventures in Spain and France. Many parliamentarians accused the king of acting unlawfully in all of these connections. The Elements of Law argued that it was the essence of government to use any means necessary to see to national security, and that people who were in fact protected by the means taken could not justly complain. On the contrary, not to cooperate with the king was a violation of duties of submission justified by the need for a single judgement to choose the means of public security. Besides, the king could not be subject to the law and also be sovereign in the strict sense.

De cive probably has the strongest claim to be the preferred statement of Hobbes’s moral and political philosophy. Hobbes himself said that with its publication he had become the inventor of civil science. Works about morals and politics published before De cive, he implied, did not rise to the level of a science, just as works in astronomy written before Johannes Kepler and Galileo did not reach the level of scientific astronomy.

At the beginning of De cive is a striking denial of the natural sociability of human beings. Human beings are not naturally suited to live in organized societies, Hobbes claims, openly contradicting the dictum of Aristotle that man is a political animal. For Hobbes, human beings have a variety of temperaments, not all of them aggressive, but were the institutions of government and the law and the enforcement of law to be taken away, no one would have a good reason not to turn aggressive. Hobbes bases this claim on three things. First, what he calls “the right of nature” or the right of anyone who depends on himself for his survival to adopt any means he thinks best to secure himself and prosper. Secondly, some common sense about what people with different temperaments are likely to do if there are no enforceable laws to stop them. For example, greedy people will take as much as they can for themselves; moderate people will refrain from aggression except to protect their reasonable share of goods, and so on. Finally, he assumes that people will mistrust one another, not taking at face value apparent moderation in others, and not hesitating to deal pre-emptively with greed. In these conditions it can be predicted that people will turn aggressive; the aggression will be blameless where the only right is the right of nature. For if each is the best judge of what is best for each, there is no gainsaying my judgement that killing you or taking anything you have by force is necessary for my survival. Even a moderate person, fearing that his neighbour is secretly greedy and ruthless, will be, or have reason to be, ruthless in anticipation, killing or dispossessing the next person before that is his own fate. And if anyone can blamelessly reach murderous judgements, life will be, in Hobbes’s famous phrase, “solitary, poore, nasty, brutish, and short” (Leviathan, ch. 13). No one will have any incentive to work or produce or share anything.

The right of nature plus distrust, plus some aggressive temperaments, makes for war, and war is the natural human condition, according to Hobbes. War also gives a point to moral and political obligations, whose function, as Hobbes saw it, was to stave off the potential for war in collective human life. The precepts of morality that would have been familiar to Hobbes’s readers—such as forgive trespasses; never bear false witness; keep your agreements—are interpreted by Hobbes as means of avoiding war or seeking peace. But in the state of nature, all of these precepts of morality oblige only to the extent that complying with them does not make one prey for other people. If it can cost you your life to keep your agreements or to forgive trespasses, then you do nothing wrong by behaving out of keeping with those precepts. The set of moral obligations in a state of war is only a wish-list. To make this wish-list into reality—to make moral precepts govern actual behaviour—it has to be made safe to act on the precepts, and this is only possible in the presence of an effective political authority or state. Only a state is able to counteract by force threats to life and property. So the moral obligation par excellence, the one that has to be met as a condition of the others being binding in practice, is the moral obligation to make peace, that is, renounce war, that is, form a state or submit to a state that already exists.

The key to making peace is for each person to lay down and transfer the right of nature. Instead of being one’s own judge of what will ensure his or her survival, each person is to delegate to someone else the right to judge what is required for collective well-being. I and my fellows in the state of nature simultaneously transfer to someone else—the same person—our individual rights to see to individual well-being. He then makes judgements, which we each have to comply with, about what will secure the well-being of many or most of us, and free us from the fear of imminent death and dispossession. The one to whom the right of nature is passed becomes sovereign and his judgements about what we must do to secure collective security and well-being are declared as civil laws, including penal laws. I transfer my right of nature to this individual on condition that everyone or nearly everyone else does so as well. If I subsequently dislike the laws that the sovereign declares, and disobey or obstruct the sovereign, then I go back on my agreement, and am guilty of injustice. I cannot complain if I transfer my right of judgement and it is exercised contrary to my judgement, for I agree not to be my own judge of what is best for me. I cannot complain of any laws the sovereign makes, so long as by following them I am not reduced to the insecurity of war. The sum total of my obligation as a citizen is to obey the law. Where the law does not prescribe what I am to do, there and there only am I free to choose means to ends, and even then only means consistent with the law. No other freedom is owed to anyone according to Hobbes.

Now the sovereign is not party to the agreement to transfer the right of nature. He does not surrender his right of nature to anyone, and he promises no one anything. If he is ineffective in making the many secure, then they are back in the state of war, and so is he, only as private enemy number one. But if he does succeed, even by means that look extreme, no one can rightly complain.

Sovereignty as conceived by Hobbes is very inclusive. The right of making war, of declaring and revising domestic law at will, of giving honours or offices, of raising taxes, of regulating trade—all of these are sovereign powers. These powers were not to be divided, according to Hobbes, or separated. If they were, that would invite power struggles within government, reproducing the state of war on a small scale and undermining the purpose of government, which is to unify a people and subdue the ingredients within them of aggressive conflict.

B.

Hobbes’s Natural Philosophy

Hobbes not only claimed to have invented civil science; he regarded himself as a pioneer, perhaps the pioneer, in the field of optics, that is, the science of the behaviour of light, the workings of sight, and the construction of instruments for seeing the very small and the very distant. As in moral and political philosophy, he regarded his optics as a new science partly because of its departure from the still influential but old Aristotelian theory of light, vision, and so on. Traditional optics had held that seeing the colour of something—a strawberry, for example—was a matter of the redness of the strawberry being reproduced in the eye and thereupon being abstracted by the mind. In Hobbes’s theory there is no need to suppose that redness is reproduced in the senses any more than the creation of the spectrum when white light passes through a prism requires one to suppose that the prism itself takes on all of the colours of the spectrum. The prism does not become coloured, but it modifies the light as it passes from the air through the material that the prism is made of. In a similar way, the eye does not become coloured when it encounters the motion of the luminous object: the experience of colour is an after-effect of the motion of the luminous object that does not resemble it at all. Hobbes also denied that the mind had the power of abstracting the content of sense experience in the way Aristotle had claimed.

Optics was a model natural science for Hobbes. Its effects could be demonstrated from clearly stated first principles, including definitions. The Short Tract on First Principles (c. 1630) arranges its material this way. So does the later Tractatus Opticus I (First Optical Treatise, c. 1640). As Hobbes’s optical theory was refined, he was able to make it more economical. The early commitment to an original substance called lumen gives way to an identification of light with the psychological after-effect of motion from a light source stimulating the animal spirits in the eye. Animal spirits were imperceptible bits of matter in circulation in the body. Hobbes came to think that there was no substance called “light”, but only motion of the dilating and contracting light source and the eye. Colour was a “phantasm” as something wholly within the mind. Eventually, Hobbes adopted the same approach to the sensible qualities in general—heat, cold, odour, taste, and sound. In the Elements of Law he says roundly that “whatsoever accidents or qualities our senses make us think there be in the world, they are not there, but are seemings and apparitions only. The things that really are in the world without us, are the motions by which these seemings are caused” (Ch. 2, ix).

The idea that accidents and qualities are purely psychological after-effects of motions of different arrangements of matter was subversive of much traditional, Aristotelian, natural science. Traditional natural science was all a matter of tracing effects to the natures of a vast array of distinct substances. These were among the things that our senses made us believe were in the world: the natures of substances were supposed to dawn on us after prolonged sense-observation. For Hobbes there was not a huge multiplicity of natures, one for each of the observationally distinct kinds of plants, animals, and so on. There were only different sizes and shapes of a uniform matter.

C.

Hobbes’s System, Hobbes’s Trilogy, and Hobbes’s Influence

Between 1642 and 1658 Hobbes published the three volumes of his Elements of Philosophy, an attempt to set out all of the sciences of body, man, and citizen from the most to least fundamental. The volumes appeared out of their proper sequence, and are very uneven in their treatment of different sciences. Hobbes’s De cive was the third of the three volumes and the first to appear. De corpore (On Body), the first volume of the trilogy, was the second to appear and talked about the methods and procedures of science in general as well as natural science in particular. De homine, the second in order but the last to appear, combined optics and psychology.

The trilogy is not a presentation of Hobbes’s own ideas. Apart from its optics and civil science, large parts of the Elements of Philosophy draw freely on the work of celebrated scientific contemporaries or predecessors of Hobbes who were all contributing to the overthrow of traditional science. Kepler, Galileo, Gassendi, and Mersenne as well as ancient mathematicians are among the sources for the sciences presented in the three volumes. But the ordering of the sciences and the way of distinguishing elements from derivative components were Hobbes’s own. He tended to present all of the sciences as dealing with different types of motion of matter, even though his moral and political sciences did not lend themselves to this description. And he insisted that the most basic science of all, apart from the science of the basic definitions of concepts used in the rest of the sciences, was geometry, followed by mechanics and physics. Moral and political science, expounded above, were derivative sciences, but also sciences that could be understood independently of the others. People had direct introspective acquaintance with some of the passions talked about by these sciences, and they would have been familiar with some moral and political obligations without knowing their scientific basis.

Although it occupied him for most of a working life that started in middle age, Hobbes’s exposition of the system of science is much less of a success than his optics or his civil science. And of the two intellectual achievements, it is the civil science that has enduring value. Virtually no other writer since Hobbes regards politics as a response to the permanent possibility of war in human life, and in our age of war and terrorist emergencies, his views have a sometimes sinister relevance.