Life and thought, biography and philosophy are inextricably intertwined in Descartes. His extremely rich correspondence, which at every step reveals important aspects of his intellectual experience, proves it beyond doubt. Descartes’s life, to paraphrase his own words, is nothing but the “story of a mind”, with uncertainties and regrets, steps backward, successes and failures. But we often read Descartes retrospectively: the early writings in the light of the Discourse, the latter on the basis of the Meditations, and the Meditations themselves with the help of the Objections and Replies and the Principles, as if a complete and well-organised Cartesian system – a “Vauban fortress”, declared Martial Gueroult admiringly – had existed from the beginning, and as if Descartes’s philosophical consciousness had gradually adapted to it. As opposed to this approach, Ferdinand Alquié attempted a different path, perhaps closer to Descartes’s own mentality: that of following his intellectual evolution step by step, analysing it in terms of a progressive “metaphysical discovery” of the depths of the human being.
However, metaphysics is not Descartes’s unique philosophical preoccupation, and it should never be severed from his physical and moral inquiries. Thus, in this book I will follow Descartes’s mind in its multiform applications and interests – from his beginnings as a mathematician and a physicist to his late reflections on morality – without taking anything for granted and almost pretending not to know what will happen next. Unlike Peter Machamer and J. E. McGuire’s Descartes’s Changing Mind (2009), where they describe Descartes’s thought as a coherent progression, characterised by distinct phases culminating in a definitive position (designated as the “epistemic stance”), this short intellectual biography does not subject the Cartesian text to a strict categorization or periodisation. Its primary focus is to clarify how that text came about, by which requirements and uncertainties it was motivated, and how it was constituted over a long period throughout Descartes’s life. For this reason, I have devoted ample space to the main philosophical debates in which Descartes found himself entangled, especially the controversy with Regius, the epistolary exchange with Princess Elizabeth of the Palatinate, and the Objections and Replies to the Meditations. The latter are generally overlooked, as is the preponderant role played by Father Mersenne in shaping them. This is mostly due, in turn, to the reluctance of most Descartes specialists to consider Mersenne as the author of the Second and Sixth Objections – that he explicitly endorses in a private text – and of the letter sent by the so-called “Hyperaspistes”, which is a continuation of the same debate. Likewise, the anonymous letter dated 19
A whole series of labels have accumulated over the years about Descartes and his thought. Much has been argued on his “methodical” or “hyperbolic” doubt, his alleged distinction between the “rule of analysis” and the “rule of synthesis”, his discovery of what others will call “analytic geometry”, his purported “spiritualism” or his “mind/body dualism” which apparently splits the human being in two (Descartes’s “error”, according to some, or Descartes’s “myth” according to others), the theory of the “animal-machine”, and even his commitment to the “cogito ergo sum” refrain – to which he was so little attached that he did not include it in his philosophical masterpiece, the Meditations on First Philosophy. These labels or formulae are often too rigid, in some cases anachronistic or even apocryphal, and conceal, at least in part, the conceptual path underlying them and the fact that they were often momentary postures and not immovable dogmas. Descartes’s thought is in continuous motion: he would not be perhaps the most studied author of the early modern period if he were not an open author, proceeding by successive approximations to truth, feeding on his own intrinsic indeterminacy. It is not in a systematic stance, therefore, that the mark of Descartes’s philosophy is to be found, but precisely in the broad waves of its internal movements, and above all in the depth of its theoretical questioning, capable of subverting established beliefs but also of continually renewing its own vitality.
With the possible exception of the political sphere, we find Descartes’s indelible imprint on all crucial debates of the early modern era, even beyond or against his own intentions: the advent of science and technology and their importance for medicine and morals, the reform and sudden crisis of metaphysics and theology, the rise of individualism, the collapse of the Aristotelian worldview and the discovery of the infinite silence of the universe. Descartes made people think the unthinkable: that matter is a geometric entity devoid of any inherent force; that human souls consist only in thought; that the order of nature is the result of simple mechanical laws and not of God’s providential design; that mathematical and moral truths are not eternal but created by God; that life depends exclusively on material factors and can be prolonged by medicine; that human passions themselves can be scientifically analysed. But Descartes also cast doubt on what seemed indubitable: the real existence of the human body and the entire material universe, the necessary truth of the
Descartes’s greatness is mainly philosophical. Important and often decisive as his contributions to the sciences were, from mathematics to physics, biology and medicine, his point of view in all these disciplines was always that of the philosopher. In all these disciplines, indeed, he always sought to investigate and test the principles, rules, general notions, and foundations, often leaving it to others to elaborate more successfully specific theorems or explanations. Surpassed in mathematics by Fermat and later by Leibniz, in physics by Huygens and Newton, exposed to easy ridicule in the life sciences because of his theories concerning the “pineal gland” and the animal-machine, Descartes surpasses everyone in the boldness of his original questioning on the foundation of knowledge, to be achieved through the asceticism of doubt. After Descartes, this was to be the philosophical question par excellence.