Thomas Hobbes (5 April 1588 – 4 December 1679), in some older texts Thomas Hobbs of Malmsbury, was an English philosopher, remembered today for his work on political philosophy. His 1651 book Leviathan established the foundation for most of Western political philosophy from the perspective of social contract theory.

Hobbes was a champion of absolutism for the sovereign but he also developed some of the fundamentals of European liberal thought: the right of the individual; the natural equality of all men; the artificial character of the political order (which led to the later distinction between civil society and the state); the view that all legitimate political power must be "representative" and based on the consent of the people; and a liberal interpretation of law which leaves people free to do whatever the law does not explicitly forbid. Hobbes also contributed to a diverse array of fields, including history, geometry, physics of gases, theology, ethics, general philosophy, and political science. His account of human nature as self-interested cooperation has proved to be an enduring theory in the field of philosophical anthropology. He was one of the main philosophers who founded materialism.

Thomas Hobbes was born in Wiltshire, England on 5 April 1588, some sources say at Malmesbury. Born prematurely when his mother heard of the coming invasion of the Spanish Armada, Hobbes later reported that "my mother gave birth to twins: myself and fear." His childhood is almost a complete blank, and his mother's name is unknown. His father, also named Thomas, was the vicar of Charlton and Westport. Thomas Sr. abandoned his three children to the care of an older brother, Thomas junior's uncle Francis, when he was forced to flee to London after being involved in a fight with a clergyman outside his own church. Hobbes was educated at Westport church from the age of four, passed to the Malmesbury school and then to a private school kept by a young man named Robert Latimer, a graduate of the University of Oxford. Hobbes was a good pupil, and around 1603 he went up to Magdalen Hall, which is most closely related to Hertford College, Oxford. The principal John Wilkinson was a Puritan, and he had some influence on Hobbes.

At university, Hobbes appears to have followed his own curriculum; he was "little attracted by the scholastic learning". He did not complete his B.A. degree until 1608, but he was recommended by Sir James Hussey, his master at Magdalen, as tutor to William, the son of William Cavendish, Baron of Hardwick (and later Earl of Devonshire), and began a life-long connection with that family. Hobbes became a companion to the younger William and they both took part in a grand tour in 1610. Hobbes was exposed to European scientific and critical methods during the tour in contrast to the scholastic philosophy which he had learned in Oxford. His scholarly efforts at the time were aimed at a careful study of classic Greek and Latin authors, the outcome of which was, in 1628, his great translation of Thucydides' History of the Peloponnesian War, the first translation of that work into English from a Greek manuscript.

Although he associated with literary figures like Ben Jonson and thinkers such as Francis Bacon, he did not extend his efforts into philosophy until after 1629. His employer Cavendish, then the Earl of Devonshire, died of the plague in June 1628. The widowed countess dismissed Hobbes but he soon found work, again as a tutor, this time to the son of Sir Gervase Clifton. This task, chiefly spent in Paris, ended in 1631 when he again found work with the Cavendish family, tutoring the son of his previous pupil. Over the next seven years as well as tutoring he expanded his own knowledge of philosophy, awakening in him curiosity over key philosophic debates. He visited Florence in 1636 and later was a regular debater in philosophic groups in Paris, held together by Marin Mersenne. From 1637 he considered himself a philosopher and scholar.

Hobbes's first area of study was an interest in the physical doctrine of motion and physical momentum. Despite his interest in this phenomenon, he disdained experimental work as in physics. He went on to conceive the system of thought to the elaboration of which he would devote his life. His scheme was first to work out, in a separate treatise, a systematic doctrine of body, showing how physical phenomena were universally explicable in terms of motion, at least as motion or mechanical action was then understood. He then singled out Man from the realm of Nature and plants. Then, in another treatise, he showed what specific bodily motions were involved in the production of the peculiar phenomena of sensation, knowledge, affections and passions whereby Man came into relation with Man. Finally he considered, in his crowning treatise, how Men were moved to enter into society, and argued how this must be regulated if Men were not to fall back into "brutishness and misery". Thus he proposed to unite the separate phenomena of Body, Man, and the State.

Hobbes came home, in 1637, to a country riven with discontent which disrupted him from the orderly execution of his philosophic plan. However, by the end of the Short Parliament in 1640, he had written a short treatise called The Elements of Law, Natural and Politic. It was not published and only circulated among his acquaintances in manuscript form. A pirated version, however, was published about ten years later. Although it seems that much of The Elements of Law was composed before the sitting of the Short Parliament, there are polemical pieces of the work that clearly mark the influences of the rising political crisis. Nevertheless, many (though not all) elements of Hobbes's political thought were unchanged between The Elements of Law and Leviathan, which demonstrates that the events of the English Civil War had little effect on his contractarian methodology. It should be noted, however, that the arguments in Leviathan were modified fromThe Elements of Law when it came to the necessity of consent in creating political obligation. Namely, Hobbes wrote in The Elements of Law that Patrimonial kingdoms were not necessarily formed by the consent of the governed, while in Leviathan he argued that they were. This was perhaps a reflection either of Hobbes's thoughts concerning the engagement controversy or of his reaction to treatises published by Patriarchalists, such as Sir Robert Filmer, between 1640 and 1651.

When in November 1640 the Long Parliament succeeded the Short, Hobbes felt he was a marked man by the circulation of his treatise and fled to Paris. He did not return for eleven years. In Paris he rejoined the coterie about Mersenne, and wrote a critique of the Meditations on First Philosophy of Descartes, which was printed as third among the sets of "Objections" appended, with "Replies" from Descartes in 1641. A different set of remarks on other works by Descartes succeeded only in ending all correspondence between the two.

Hobbes also extended his own works somewhat, working on the third section, De Cive, which was finished in November 1641. Although it was initially only circulated privately, it was well received, and included lines of argumentation to be repeated a decade later in the Leviathan. He then returned to hard work on the first two sections of his work and published little except for a short treatise on optics (Tractatus opticus) included in the collection of scientific tracts published by Mersenne as Cogitata physico-mathematica in 1644. He built a good reputation in philosophic circles and in 1645 was chosen with Descartes, Gilles de Roberval and others, to referee the controversy between John Pell and Longomontanus over the problem of squaring the circle.

The English Civil War broke out in 1642, and when the Royalist cause began to decline in the middle of 1644 there was an exodus of the king's supporters to Europe. Many came to Paris and were known to Hobbes. This revitalised Hobbes's political interests and the De Cive was republished and more widely distributed. The printing began in 1646 by Samuel de Sorbiere through the Elsevier press at Amsterdam with a new preface and some new notes in reply to objections.

In 1647, Hobbes was engaged as mathematical instructor to the young Charles, Prince of Wales, who had come over from Jersey around July. This engagement lasted until 1648 when Charles went to Holland.

The company of the exiled royalists led Hobbes to produce an English book to set forth his theory of civil government in relation to the political crisis resulting from the war. The State, it now seemed to Hobbes, might be regarded as a great artificial man or monster (Leviathan), composed of men, with a life that might be traced from its generation under pressure of human needs to its dissolution through civil strife proceeding from human passions. The work was closed with a general "Review and Conclusion", in direct response to the war which raised the question of the subject's right to change allegiance when a former sovereign's power to protect was irrecoverably gone. Also he criticized religious doctrines on rationalistic grounds in the Commonwealth.

During the years of the composition of Leviathan he remained in or near Paris. In 1647 Hobbes was overtaken by a serious illness which disabled him for six months. On recovering from this near fatal disorder, he resumed his literary task, and carried it steadily forward to completion by the year 1650. Meanwhile, a translation of De Cive was being produced; there has been much scholarly disagreement over whether Hobbes translated the work himself or not.

In 1650, a pirated edition of The Elements of Law, Natural and Politic was published. It was divided into two separate small volumes (Human Nature, or the Fundamental Elements of Policie and De corpore politico, or the Elements of Law, Moral and Politick). In 1651 the translation of De Cive was published under the title of Philosophicall Rudiments concerning Government and Society. Meanwhile, the printing of the greater work was proceeding, and finally it appeared about the middle of 1651, under the title of Leviathan, or the Matter, Forme, and Power of a Common Wealth, Ecclesiasticall and Civil, with a famous title-page engraving in which, from behind hills overlooking a landscape, there towered the body (above the waist) of a crowned giant, made up of tiny figures of human beings and bearing sword and crozier in the two hands.

The work had immediate impact. Soon Hobbes was more lauded and decried than any other thinker of his time. However, the first effect of its publication was to sever his link with the exiled royalists, forcing him to appeal to the revolutionary English government for protection. The exiles might very well have killed him; the secularist spirit of his book greatly angered both Anglicans and French Catholics. Hobbes fled back home, arriving in London in the winter of 1651. Following his submission to the council of state he was allowed to subside into private life in Fetter Lane.

In Leviathan, Hobbes set out his doctrine of the foundation of states and legitimate governments - based on social contract theories. Leviathan was written during the English Civil War; much of the book is occupied with demonstrating the necessity of a strong central authority to avoid the evil of discord and civil war. Beginning from a mechanistic understanding of human beings and the passions, Hobbes postulates what life would be like without government, a condition which he calls the state of nature. In that state, each person would have a right, or license, to everything in the world. This, Hobbes argues, would lead to a "war of all against all" (bellum omnium contra omnes), and thus lives that are "solitary, poor, nasty, brutish, and short". To escape this state of war, men in the state of nature accede to a social contract and establish a civil society. According to Hobbes, society is a population beneath a sovereign authority, to whom all individuals in that society cede their natural rights for the sake of protection. Any abuses of power by this authority are to be accepted as the price of peace. However, he also states that in severe cases of abuse, rebellion is expected. In particular, the doctrine of separation of powers is rejected: the sovereign must control civil, military, judicial and ecclesiastical powers.

Leviathan was also well-known for its radical religious views, which were often Hobbes's attempt to reinterpret scripture from his materialist assumptions. His denial of incorporeal entities led him to write, for example, that Heaven and Hell were places on Earth, and to take other positions out of sync with church teachings of his time. Much has been made of his religious views by scholars such as Richard Tuck and J.G.A. Pocock, but there is still widespread disagreement about the significance of Leviathan's contents concerning religion. Many have taken the work to mean that Hobbes was an atheist, while others find the evidence for this position insufficient.

Hobbes now turned to complete the fundamental treatise of his philosophical system. He worked so steadily that De Corpore was first printed in 1654. Also in 1654, a small treatise, Of Liberty and Necessity, was published by Bishop John Bramhall, addressed at Hobbes. Bramhall, a strong Arminian, had met and debated with Hobbes and afterwards wrote down his views and sent them privately to be answered in this form by Hobbes. Hobbes duly replied, but not for publication. But a French acquaintance took a copy of the reply and published it with "an extravagantly laudatory epistle." Bramhall countered in 1655, when he printed everything that had passed between them (under the title of A Defence of the True Liberty of Human Actions from Antecedent or Extrinsic Necessity). In 1656 Hobbes was ready with The Questions concerning Liberty, Necessity and Chance, in which he replied "with astonishing force" to the bishop. As perhaps the first clear exposition of the psychological doctrine of determinism, Hobbes's own two pieces were important in the history of the free-will controversy. The bishop returned to the charge in 1658 with Castigations of Mr Hobbes's Animadversions, and also included a bulky appendix entitled The Catching of Leviathan the Great Whale. Hobbes never took any notice of the Castigations.

Beyond the spat with Bramhall, Hobbes was caught in a series of conflicts from the time of publishing his De Corpore in 1655. In Leviathan he had assailed the system of the original universities. Because Hobbes was so evidently opposed to the existing academic arrangements, and because De Corpore contained not only tendentious views on mathematics, but an unacceptable proof of the squaring of the circle (which was apparently an afterthought), mathematicians took him to be a target for polemics. John Wallis was not the first such opponent, but he tenaciously pursued Hobbes. The resulting controversy continued well into the 1670s.

Hobbes published, in 1658, the final section of his philosophical system, completing the scheme he had planned more than twenty years before. De Homine consisted for the most part of an elaborate theory of vision. The remainder of the treatise dealt cursorily with some of the topics more fully treated in the Human Nature and the Leviathan. In addition to publishing some controversial writings on mathematics and physics, Hobbes also continued to produce philosophical works. From the time of the Restoration he acquired a new prominence; "Hobbism" became a byword for all that respectable society ought to denounce. The young king, Hobbes's former pupil, now Charles II, remembered Hobbes and called him to the court to grant him a pension of £100.

The king was important in protecting Hobbes when, in 1666, the House of Commons introduced a bill against atheism and profaneness. That same year, on 17 October 1666, it was ordered that the committee to which the bill was referred "should be empowered to receive information touching such books as tend to atheism, blasphemy and profaneness... in particular... the book of Mr. Hobbes called the Leviathan". Hobbes was terrified at the prospect of being labelled a heretic, and proceeded to burn some of his compromising papers. At the same time, he examined the actual state of the law of heresy. The results of his investigation were first announced in three short Dialogues added as an Appendix to his Latin translation of Leviathan, published at Amsterdam in 1668. In this appendix, Hobbes aimed to show that, since the High Court of Commission had been put down, there remained no court of heresy at all to which he was amenable, and that nothing could be heresy except opposing the Nicene Creed, which, he maintained, Leviathan did not do.

The only consequence that came of the bill was that Hobbes could never thereafter publish anything in England on subjects relating to human conduct. The 1668 edition of his works was printed in Amsterdam because he could not obtain the censor's licence for its publication in England. Other writings were not made public until after his death, including Behemoth: the History of the Causes of the Civil Wars of England and of the Counsels and Artifices by which they were carried on from the year 1640 to the year 1662. For some time, Hobbes was not even allowed to respond, whatever his enemies tried. Despite this, his reputation abroad was formidable, and noble or learned foreigners who came to England never forgot to pay their respects to the old philosopher.

His final works were a curious mixture: an autobiography in Latin verse in 1672, and a translation of four books of the Odyssey into "rugged" English rhymes that in 1673 led to a complete translation of both Iliad and Odyssey in 1675.

In October 1679, Hobbes suffered a bladder disorder, which was followed by a paralytic stroke from which he died on 4 December 1679. He is said to have uttered the last words "A great leap in the dark" in his final moments of life. He was interred within St. John the Baptist Church in Ault Hucknall in Derbyshire, England.