In the 16th and 17th centuries, Protestants invaded Catholic territories both geographic and ideological. Armed with sharp invectives and printing presses, anti-Catholic firebrands overturned centuries-old accounts of God and the natural world, flooding markets with new bibles, new confessional literatures, and new treatises of astronomy, astrology, medicine, alchemy, and magic. The Catholics reacted with ultimately futile attempts to limit the contagion of heresies, prohibiting books and authors and doing everything they could to stop their publication. But as the Reformation became institutionalized and protected by princely powers, the revolution could not be stopped, and the modern world was made.
The hottest fighting was in the areas of religion and science – in the broadest strokes, Luther vs. the pope, and Copernicus vs. Ptolemy. But tightly implicated in both religion and science was metaphysics, the philosophical understanding of matter, spirit, and causality. Medieval Catholicism had found ingenious ways to appropriate Aristotle’s metaphysics in its various accounts of the world. But the oncoming deluge of new books, and the radical ideas contained in them, placed new disruptive pressures on the standard metaphysical accounts. Just as Ptolemy’s theory of the heavens started to wobble, Aristotle’s account of substance, essence, and accident became increasingly suspect. Galileo demonstrated success in applying mathematics and geometry directly to moving bodies – without needing to work out any of the Aristotelian substantial forms. When it came time to explain and predict, his Simplicio was no match for his Sagredo.
So there was a philosophical challenge to be met in the wake of the early modern rebellion. The challenge was to find a new metaphysics to go with the new science – and along with that, a new metaphysics of human beings and their ways of coming to know themselves, the world, and God. The good news and the bad news was simultaneously this: everything was up for grabs.
Not all the philosophers saw the challenge in the same way. For the most ambitious among them – Bacon, Comenius, Descartes, Newton, and Leibniz – the challenge was to co-establish traditional religion and the new sciences, each perfect and together complete: a new System of the World. For Spinoza – and, much later, the German Idealists – the challenge was to surmount old-style thinking in a radical way that transcended (and yet, in true Hegelian fashion, also preserved) both the new physics and traditional monotheism. For Hobbes, Locke, Pascal, and Bayle, the challenge was to negotiate a middle way between the Scylla of religious zealotry (those many snapping mouths) and the Charybdis of godless scientism (that all-consuming, sucking vortex). So there you have it: the Establishers, the Transcendentalists, and the Negotiators. All of them sought some way past Aristotle and past the entrenched positions of myriad religious confessions. At stake for each of them was the future of Europe.
It is imperative not to be so seduced by the intrinsic glory of their philosophical thoughts that the historical and political contexts of these philosophers is ignored. True: what they wrote stands the test of time. But to see them in context, to see their intellectual moves in a world being torn apart by cannon and treaty, is to accord them proper humanity; and thus to make them more real to us than any disembodied mind can be. When Spinoza wrote to Henry Oldenburg and compared our ignorant place in the universe to that of a little worm in someone’s bloodstream, he was not merely invoking the theme of the microcosm in the macrocosm. He was writing to a friend across a channel where two hundred English and Dutch ships had recently clashed and sent three thousand men to watery graves; he was writing to a friend whose city (like his own) was being ravaged by plague, and who was about to be sent to the Tower on suspicion of treason; and he was writing as a man who before long would himself succumb to the blind actions of a worm in his blood, mycobacterium tuberculosis. Spinoza’s advice – to see the universe as determined to follow its own laws, and to console ourselves by turning our minds to what is eternal and divine – was not just pretty words; it was offered as a palliative for existential anxiety and despair. When we ignore their complicated circumstances, we risk mistaking these philosophers for university professors, with nothing more at stake than records of publication. These philosophers regularly saw the corpses piling up from bad politics, angry religions, and ignorant doctors; and – strange as it may sound to us – they believed a better metaphysics could help reduce their number.
But how did they deploy their metaphysical insights? For it is not enough just to think them up. They had to be shared, published, promoted, or poured directly into the ears of those in power. All of them wrote books and letters that were meant for wider circulation. Some of them crafted proposals to be sent directly to electors and princesses, dukes and emperors. Some of them tried to establish societies of savants, in the hope that the impact of a larger group would have greater effect. One of them (Spinoza again) was ready to put his opinion on a sandwich board and march directly into a hostile mob. Translating ideas into impact required then, as now, shrewd thinking about audience, rhetoric, and medium. This very practical business – the marketing department of philosophical enlightenment, as it were – must always be borne in mind when coming to grips with a philosophical text. It does not pay, on every occasion, to say directly what one thinks is true; nor is it wise to alienate those who are in a position to advance the cause.
It must also be borne in mind that, in a very real sense, none of these philosophers had a firm grip on reality. Not because they were crazy, of course, but because the state of knowledge was – in hindsight – very confused: alchemy and astrology shouldered up against early physics, the distinction between magic and natural change was fuzzy at best, and political philosophy was often imbued with millenarian enthusiasm. Newton himself thought the mystery of alchemy might explain gravity’s otherwise “spooky” action at a distance. We may find amusement today over the Royal Society’s early discussions of stones found in the skulls of venomous snakes that were said to draw poison from wounds, of patients in whose veins ran milk instead of blood, and of salamanders living quite comfortably in fire; but these accounts run alongside much more practical observations of sea tides and expedient methods for crafting lenses. It was all of a piece; and philosophers seeking an adequate metaphysics often found themselves trying to accommodate an exceedingly generous range of seemingly authentic observations. Endeavors to found universal learned societies were often predicated on the expectation that Christ’s rule on earth was about to begin; arguments that clarified and fortified Protestant Christianity were mounted in the hope of converting the Jews, a prerequisite for the end times. It was, by our lights, a weird and wacky world; though of course to the people living in it, it was of course just – the world.