A Natural Philosopher

...Since there could be no void, a priori, hence no motion without a tangible force behind it, he did not conceive of action at a distance...

...Clarke, having absorbed so much personal detail, can't resist using it exhaustively, occasionally clouding shape, proportion, and significance...

...In those uncertainties he had distinguished company...

...He limned what would be known as Newton's laws of inertia...

...In his self-imposed isolation he lacked the reinforcement that Newton would find, a generation later, at Cambridge and in the Royal Society, where generous contemporaries would ratify his genius...

...that is, the first great thinker of the Western tradition to view mathematics rather than theology as the sovereign key to the cosmic mysteries—and the cosmos itself as something like an autonomous machine...

...Clarke gets a pass for dwelling here at extreme length on the merely personal...

...Jesuit college at La Flèche soon quit his native France (first as an officer in a Dutch army, then permanently) and passed almost all the rest of his life in obscure towns in the northern Netherlands...

...But Descartes's theory of inertia and his vortex theory of planetary motion were ingenious...

...At a time when Galileo was forbidden to teach the heliocentric theory (and even speculations about rainbows could be censored and punished), Descartes addressed all the issues of the infant physics: optics, motion, ballistics, astronomy, even anatomy...

...What later ages (up to Einstein) would call the "ether" he considered to be an invisible medium of swirling corpuscles, whose whirlpool-like vortices accounted for the motion of planets...

...A loner, he often spent his mornings in bed, read few books (he claimed) and collected fewer, especially if they were critical of him...

...Documentation, aside from letters, is exiguous...

...His is often described as the first "mechanical philosophy...

...But their speculations are often ludicrously wrong...

...Galileo scoffed at Kepler's suggestion that the moon might influence tides...

...Descartes is usually identified as the father of philosophical dualism, the creator of the dilemma posed by the gap between mind and matter...

...He especially evaded discussion of such tricky matters as transubstantiation...

...Clarke's is the sort of biography we rightly call magisterial, and it is hard to imagine that anyone will ever know as much as he does about this reclusive prodigy, whose name and most famous assertion ("I think, therefore I am") are better known than his actual accomplishments...

...He believed, as most contemporaries did, that nature abhors a vacuum, so that the movement of heavenly bodies disclosed by the telescope needed some propellant...

...Newton saw Descartes as his most important precursor and took great pains in the Principia to disconfirm the vortices...

...Eliot's dissociation of sensibility had not yet occurred) as they appeared to Descartes, Galileo, Kepler, and other giants...

...So he conducted a lifelong fencing match with the Jesuit fathers, seeking their imprimatur on his writings and pretending to adjust his speculations to the doctrines of Counter Reformation Catholic orthodoxy...

...But the book has the defect of its virtues...

...He did posit a theory of "animal spirits" flowing through long bodily tubes and connecting mind and matter...

...This, of course, was the sort of tautology of which Molière, his near contemporary, made comic sport...

...Clarke never really decides what prompted Descartes's constant shuttling from hamlet to hamlet, though there are insinuations of debt and sexual irregularity...

...It isn't clear why this brilliant graduate of the Edwin M. Yoder Jr...

...Since he has written an earlier book on Cartesian science, Dr...

...It would seem that the empiricism of Protestant England offered a more congenial climate for experimental science than the theology-ridden Continent...

...is a former editor and columnist in Washington...

...He called it a "puerility...

...Descartes was the father of analytic geometry...

...His pen pal, the young Princess Elizabeth of Bohemia, pressed him to explain how pure thought, being immaterial, could will the movement of a limb or a muscle...

...Philosophers do not often lead adventurous lives, and Descartes is no exception...

...Still, if you want to know all that is now knowable about one of the great figures of the Western tradition, it's all here...

...Futurologists, so-called, try to imagine the next age...

...Even in the history of science—especially there—it is easy to slight the brilliant figures, including the subject of this biography, who lived and worked in a pre-Einstein, pre-Darwinian and, more to the point, pre-Newtonian world...

...He parried her question, probably because he had no good answer...

...The inescapable hazard of historical inquiry is that, as we explore time past, we become Whigs in Herbert Butterfield's sense: prisoners of the categories and verdicts in which our own age is steeped, ratifying what time has established...

...What we can do, more reliably, is try to view the problems of 17th-century "natural philosophy" (as science was then still called, for Mr...

...Then there was the Inquisition, a real if distant threat...

...And I do mean all...

...In Descartes, one has the impression of a brilliant speculator groping in predawn dimness...

...Not even his great successor, Isaac Newton, reached certainty about the nature of the force he subdued to calculus and called universal gravitation...

...One possible explanation is that Descartes was fleeing Jesuit influence, actual or imagined...

...Descartes, who came of the high gentry and enjoyed the independence of inherited wealth, emerges as a cranky, solitary, and often quarrelsome man even with friends...

...The Jesuits had educated him in the scholasticism of that age and continued to dominate the intellectual climate of France...

...In fact, he kept the company of Protestants—even Calvinists, unavoidable in Holland, though he detested their outlook—and was critical of the thought patterns that had structured Catholic orthodoxy for ages, with its proliferating entities...

...He never married but fathered an illegitimate daughter by a maidservant...

...He realized that some force must account for planetary motion and that such motion involved a mathematical relationship between arcs and their tangents...

...It was a tribute of sorts, albeit negative...