Pierre Gassendi was born in Champtercier in Provence, on 2 January 1592, the son of a peasant, and died in Paris on 24 October 1655. He studied Latin and rhetoric in Digne (1599–1607), then philosophy in Aix, and became a teacher of rhetoric in Digne (1608) and of philosophy in Aix (1611), following his father’s death. He received a doctorate in theology in Avignon in 1614. He travelled to Paris in 1615 and was then appointed as philosophy teacher in Aix (1617). After the Jesuits withdrew his chair in 1621, he retired to the Provence mountains to devote himself to astronomy and philosophy.
Gassendi became canon of Digne Cathedral in 1623 and then provost in 1625; the responsibilities of his position led to endless trials. After a trip to Paris in 1624, he spent some time in Grenoble in 1625, then returned to Provence before settling for four years in Paris from 1628 to 1632, a period that was interrupted only by a trip to The Netherlands from 1628 to 1629 – the only trip he made there – accompanied by François Luillier , who became his best friend. From 1632 to 1641, Gassendi lived in Provence; this period was marked by his friendship with Peiresc and the death of this dear friend in 1637, an event which affected him for a long time. He also showed the first signs of an illness (perhaps tuberculosis or malaria). In 1639, he met Louis de Valois, the governor of Provence, who became his new protector; he entered into a rich and long correspondence with Valois, until the latter’s death in 1653. Valois supported him at the beginning of his ecclesiastical career: he was elected an agent of the clergy (representing prelates at the Assemblée du Clergé de France, an assembly called by the king in order to deal with temporal matters and, particularly, with relations between Church and state; this post opened up a brilliant ecclesiastical career for him) and left for Paris in 1641, but was forced to resign from his post on account of political intrigue. He abandoned his work, but had to face continual trials. In Paris, he became involved in a double controversy against Descartes , related to the Meditationes de Prima Philosophia, and against Jean-Baptiste Morin (concerning the movement of the earth and astrology). In 1645, on Alphonse de Richelieu recommendation and after numerous prevarications, he became a teacher at the Collège royal, on the exceptional condition that he could return to his studies if his health obliged him; he taught astronomy more than mathematics. Four years later, an inflammation of the lungs and some personal difficulties – perhaps the death of Mersenne and pressing calls from Valois – made him return to Provence, passing first through Lyons, where he published his works on Epicurus in 1649. In 1650, in Toulon, he repeated the barometric experiment, the so-called Puy-de-Dôme experiment (showing the existence of the void and the weight of air by measuring atmospheric pressure) with Luillier, who then left for Italy, where he died. Gassendi returned to Paris in 1653 and lived at the Hôtel de Montmor, where his illness grew worse. Guy Patin bled him nine times in a row and then five more times, which perhaps accelerated his death; he demanded the viaticum and extreme unction three times and died reciting the Psalms.
Gassendi is always quoted but, in fact, is little known; his thought is often distorted, indeed, scorned. The reasons for this are varied: his works are not easily accessible (written in a difficult form of Latin); his epigones had a bad reputation ( Chapelle , Cyrano de Bergerac ); Cartesianism defeated him in the end, and his discreet and modest character did not help to disseminate his ideas. His eminently baroque style of composition and thought – with its heavy reliance on irony and its hostility to clear-cut affirmations – is disconcerting, as is his use of references and quotes, often interpreted as an accumulation, whereas they in fact come from a choice that has a theoretical foundation and from the desire to invent a philosophical language corresponding to the singular composition of the nature of things and of thought (nothing is new because the number of atoms is determined at the outset; yet everything is always new because the atoms regroup in unexpected configurations); the aim is also to respond to the mind’s need to produce genealogies (critical histories of phenomena) in order to conceive and create progress
The demanding invitation to become erudite in order to be free, defined as a form of audacity in the autonomous subject’s self-affirmation against authority, which Gassendi borrowed from Horace and which was the object of his motto Aude sapere (dare to know), implies a particular relationship to knowledge: to be ignorant is to risk rediscovering what is already known, thereby losing precious time in terms of the progress that needs to be made; it is, above all, to be unable to situate inventions, in the broadest sense, in the context of their connections and their history. Erudition is never an end in itself, being too close to pedantic pretention, but, rather, it is subordinate to a moral requirement. Finally, like Mersenne, to whom he was close in many respects, Gassendi crossed the lines of opposition put in place by historiography, since he was both materialistic and spiritual, sceptical and dogmatic, a man of science and a man of the Church (he never missed a night-time observation nor a mass); he was an upholder of the new science yet hostile to the idea of making mathematics the language of the universe. His activity as a scholar was always subordinate to a strictly philosophical goal, with the aim of freeing the mind of all forms of dogmatism that only knowledge allowed one to criticize legitimately. Without having a methodical mind, he thus represented a highly integrated form of philosophy in which all the component parts correspond to each other, while founding the theory of his future achievements.
Gassendi is known primarily for his opposition to scholastic philosophy, against which he published, in 1624, the first book of his Exercitationes paradoxicae, which follows the Baconian practice of challenging the authorities, a priori interpretation and recent tradition, with the intention of replacing them with experimental proof. This work, published at the same time as that of Garasse and the affair of the atomists Bitault, Villon and de Clave , perhaps caused its author to run some risks; from then on, he concentrated on his astronomy to which he devoted his night-time observations, ever since Joseph Gaultier, prior of Valette and a close friend of Galileo, had introduced him to observational astronomy: he was committed to demonstrating the earth’s movement and supported Galileo unfailingly, along with Peiresc who was his first protector and friend (he published a Vie de Peiresc in 1641); he wrote a method of observation, recording all his data, ‘brutal, bare and crude’ (‘brutes, nues, crues’), in a diary between 1618 and 1652 and was encouraged to carry out and then publish major observations, often using Galileo’s telescope, in support of the Copernican theory (Passage de Mercure devant le soleil, 1631; a cartography of the moon in collaboration with Claude Mellan; observations of the apparent height of the sun; sunspots; the moon, comets and eclipses, including that of 1635, which enabled maps of the Mediterranean to be corrected by 1000 kilometres); other scientific work based on experiments and observation (mechanisms of vision, the circulation of the blood, the swinging of a pendulum, the fall of a body) enabled him to take his place among those who upheld the new science. He attended meetings organized by Mersenne in the convent of the Minimes and led scholarly meetings held at the Hôtel de Montmor, which constituted the embryo of the future Académie des sciences. He upheld, in particular, the existence of the void. His opposition to Aristotle and to his dogmatism should also be seen in the context of his struggle against esoteric and theosophical trends and against occultist dogmatism: he distinguished himself, along with Marin Mersenne and Gabriel Naudé , by publishing a book directed against the Rosicrucians, Epistolica exercitatio (1630). His reading of Herbert of Cherbury’s book (1634) and his proposed refutation of the zetetic method should be added to his struggle against all forms of dogmatism, in this case, intuitionist dogmatism. His recognition of the evidence of the senses and of the positive nature of the imagination was to play a major role in his questioning of Cartesian rational evidence and metaphysical dogmatism (eternal truths).
This intellectual commitment to the struggle against dogmatism did not make Gassendi a sceptic; on the contrary, all his critical interpretations of the modern and ancient philosophers (to these should be added his refutation of Stoic destiny and the affirmation of man’s moral freedom) came from a reversal of scepticism; exercising isosthenia did not serve to demonstrate irreconcilable differences but, rather, to find possible points in common. His interpretation found expression in his rediscovery of Epicurus and the philosophy of the Garden, which he first used to restore (philo-logical restoration of book X of Diogenes Laertius, which contained the main ideas of what survived of Epicurus’ philosophy, and a collection of all the texts and accounts concerning Epicurus from pagan and Christian antiquity, by both philosophers and poets) and to comment (Animadversiones, 1649), by discerning the criteria or markers of Epicureanism and then to present (Syntagma philosophiae Epicuri, 1649) in the framework of the fiction of an Epicurus who had come back to life and presented his doctrine according to the Hellenistic divisions of philosophy (logic, physics, ethics). Conscious of the fact that Epicurean philosophy could not be accepted while its inventor suffered the bad reputation that he had acquired since antiquity and which Christianity had passed on, Gassendi studied the life and morals of Epicurus in order to reveal the slander and to restore Epicurus’s integrity from a moral perspective (De vita et moribus Epicuri, 1647). His interest in the life and morals of scholars and philosophers, which allowed theory to be coupled with a practical dimension, is shown in the biographies of astronomers that he wrote at the end of his life (1654). Epicurus’s moral rehabilitation led Gassendi to reflect on Epicurus’s Gods and, through a new synthesis, to surpass the contradiction which he had initially observed between Christianity and Epicureanism: this synthesis is clearly announced in the Syntagma philosophiae Epicuri insofar as he preceded certain chapters by refutations put forward in his own name (on Providence, the infinite number of atoms and the creation by God). This new synthesis led him to conceive his own philosophical system, the Syntagma philosophicum, published posthumously in the edition of his complete works, undertaken by Habert de Montmor (1658). In this work he presented Epicurean logic, ethics and atomism, and maintained the existence of God the creator, of providence rather than chance and of the spirituality and immortality of the soul. He thereby presented Christian thought on the foundations of Epicurean philosophy; he developed Epicurus’s political and legal thought and deepened his notion of model and example.
He reformulates Epicurean logic so that it can serve as a basis for the new science and for his empirical methods, and he draws up a theory of errors and verification. The logic of the Syntagma philosophicum, the Institutio logica, begins with an overview of the different forms of logic invented and formulated since the origin of thought up to that of Descartes, before going on to present Epicurean logic, divided into canons that attribute a fundamental role to the senses, once they have been clearly distinguished in their different domains: the true idea of a thing represents it correctly as it is apprehended by the senses; falseness and error are to be attributed to opinion and judgement and not to perception. After defining the role and the limits of prenotions, he holds that all questions revolve around things or words, and establishes three criteria for truth: sensations, anticipations, the passions, that correspond respectively to the senses, the intellect and the appetite, and focus respectively on sensitive things, on intelligible things and on the actions of life.
Logic is a necessary prerequisite for studying physics, which is based on the fact that there exists something true that can be judged and known. The relation of logic to physics is that of theory to practice. Unlike Epicurus, for whom the moral dimension is paramount (physics must be studied in order to calm one’s fears and thus for each phenomenon he proposes a multiplicity of possible explanations, without concerning himself over the real cause), Gassendi considers the moral aspect to be necessary but insufficient; the desire for knowledge finds its place in the divine project and Gassendi regards scrutiny of the spectacle of the world as a means of active prayer that enables man to grow closer to the Creator. He searches, if not for the true functioning of the universe, which he regards as inaccessible to man, at least for a convincing approximation; the harmony of the universe and its capacity to function by its own forces, laws and physics, without the intervention of any supernatural agent, were the proof of the existence, the goodness, the perfection of God, who does not mix with his creatures, not even with the sun or with nature as a whole. Gassendi also rejects all forms of deism. He envisages physics, according to its etymology, as the study of everything that exists in the universe from the point of view of generation, that is, the universal nature of things and the singular nature of each thing; in other words, everything that is born and everything that is the cause of that generation. The nature of things is composed of atoms, void and a third substance: incorporeal nature. Sensation provides proof of atoms; movement provides proof of the void and the fact that there are things that are inaccessible to perception is, by induction, the proof that there is a third substance. The void is a space which remains the same independently of the presence or absence of a body within it (in the same way, time is a space that is independent of events that take place in it); in this space of infinite void, of which the world occupies only a minute part, the atoms move around and collide to combine and form worlds. Gassendi studies physics in four parts: the universe, which is infinite (the birth and death of things, their movement and their transformations, their varied qualities); next, the world, as a part of the universe (nothing, conceptually, prevents a plurality of worlds, but at the level of existence, God conceived only ours); the sublime (astronomical and meteorological phenomena); and, finally, terrestrial things, both inanimate and animate. The universe as a whole does not change, since it is a totality and is infinite, but the things that compose it, the worlds, are in continual transformation. This implies that man’s point of view is relative (the infinite universe has neither centre nor circumference; the idea of a centre/middle is relative to the world and not to the universe) and that, as regards the vicissitude of everything, the universal flux unfolds inside the permanence of the sum total of things.
The idea that philosophy could be synchronically and diachronically the basis for the structure of man’s thought (his soul is, on the one hand, sensitive or vegetative, and, on the other hand, rational, comprising both intellect and will), and that we must not, therefore, oppose reason and faith, materialism and spiritualism, but rather combine them, comes from Gassendi’s linear conception of history, which can also be found in Epicurus. For Gassendi, human history is marked by the evangelical Revelation and must be completed by the final Judgement, of which man can know nothing. Negative theology in the tradition of Nicholas of Cusa thus goes hand in hand with epistemological optimism in a theory of progress and of strictly atomistic accumulation. It is in this context that the quarrel with Descartes should be interpreted, in the sense of a refusal of the notion that logic or mathematics may be the very language of God, whose freedom and infinite character must not be subjected to any limitation or restriction.
Making ethics the primary concern and the ultimate question of philosophy, Gassendi proposes pleasure as the aim of man and of philosophy; philosophy should be practised by everyone, regardless of age, sex, social background or geographical origin, as an exercise leading towards a happy, or rather, a happier life (with the accumulation of pleasure coming from study, friendship, enjoying the spectacle of the world, etc.), insofar as man can only, by essence, experience pleasure in movement and not at rest, since happiness in rest is reserved for God. Happiness consists of an absence of pain in the body and a tranquility of the mind, but perfection, a form of immobile enjoyment, is not accessible to man whose nature, being composed of atoms and void, and subject to generation and corruption, implies a movement of parts; philosophical exercise is, therefore, a movement appropriate to man searching for pleasure. However, as morality comprises two aspects – theoretical and practical – this dual character prohibits a presentation disengaged from all circumstance: an abstract account. The utmost pleasure as an aim can be achieved only through a continued effort on the part of the subject. Gassendi’s choice of the biographical genre is linked to this need to study morality through customs and within a context. Man’s freedom, firmly linked to the affirmation of divine Providence, is one of the points of articulation of his philosophy as a whole, which challenges both destiny and chance; God’s creation of man, an act of love free from physical need, alone guarantees man’s freedom and forces him to engage in moral reflection, insofar as he has nothing that can provide him with sound moral guidance in life, unlike animals which have instinct; either he submits to habit or to passion, or he exercises his responsibility and his freedom, based on philosophical activity nourished by erudition.
Gassendi’s skill as an adviser to the governor of Provence at the time of the Fronde troubles inspired him to form an anti-Machiavellian conception of politics, one that was close to that of his friend Hobbes (he wrote a preface to the first French edition of De cive), who invited him to reformulate the relations between the prince and philosophy. Going against the prejudice according to which Epicurism condemns political activity, Gassendi proves that, far from tarnishing the reputation of a man of state and restricting him to the banality of everyday life, philosophy, on the contrary, enhances politics, and it is not necessary to abandon all concern for the state in order to study philosophy. Politics is not a responsibility that separates the prince from true virtue, but a sort of election: whoever assumes it must lead others to goodness, offering himself as a model or example.
Gassendi’s complete works, the posthumous publication of which he had organized, contain a fascinating correspondence in Latin (1621–54), demonstrating the integrated nature of his philosophy and the vitality of epistolary networks at the time.
Exercitationvm paradoxicarvm aduersus Aristoteleos Libri septem (Grenoble, 1624; Dissertations en forme de paradoxes contre les Aristotéliciens, bks I and II, ed. and trans. Bernard Rochot, Paris, 1959).
Disquisitio metaphysica, seu dubitationes et instantiae adversus Renati Cartesii metaphysicam et responsa (Amsterdam, 1644; Recherches métaphysiques, ou doutes et instances contre la métaphysique de R. Descartes et ses réponses, ed. and annotated by Bernard Rochot, Paris, 1962).
Recueil des lettres des sieurs Morins, de la Roche, de Neuré et Gassend en suite de l’apologie du sieur Gassend, touchant la question De motu impresso a motore translato. Où par occasion il est traité de l’astrologie judiciaire (Paris, 1650).
Libertins du dix-septième siècle, under the supervision of Jacques Prévot (Paris, 1998); trans. by Étienne Wolff of pt 3 of Philosophiae Epicuri Syntagma, devoted to ‘Ethics or morals’; presentation and annotation by Thierry Bedouelle.