WE were once taught that after having slept soundly through “the Dark Ages,” Europe was suddenly awakened in 1453 by the Fall of Constantinople. We now know that it had been light all the while and that Europe had, to say the least, been in a very lively state of somnambulism. We know that for many centuries before 1453 men had been living very intensely and very nobly; and with a seriousness and elevation of thought that have perhaps had no parallel. The age that created Gothic art, and dreamed so splendid a dream as the Holy Roman Empire, can scarcely be said to be lacking in imagination and enlightenment.
But that something important happened to the European mind in and about the fifteenth century no scholar is so iconoclastic as to deny. It was not so much an awakening of thought as a change of direction which proved in the sequel to be amazingly fruitful. It may perhaps best be described as a return to the sources. This is characteristic of all of its more notable manifestations, such as the retrospect of antiquity, the reexamination of institutions, and the more direct observation of nature. This turn of thought back to the originals and roots of things, this general freshening up by the admixture of new experiences, had its effects upon every interest and work of man. So there was, among other things, a Renaissance philosophy, which meant chiefly a new study of some ancient philosophy. Pico of Mirandola founded a new cult of Plato; Pomponatius defended the Greek or Alexandrist interpretation of Aristotle against the Averroist and orthodox interpretations; while Montaigne 1 revived the ancient scepticism. But what was more significant for the future of philosophy, came not directly through the influence of the spirit of the age upon philosophy, but through the influence of this spirit first upon science, and, indirectly through science, upon philosophy. The great men of the age, so far as the future of philosophy is concerned, were not Pico and Pomponatius, but Copernicus and Galileo.
THE COPERNICAN DISCOVERY
Copernicus 2 ventured to assert that the earth moved. He could scarcely have astonished and disturbed men more if he had actually set it moving. The belief in the earth as the firm center of creation, lighted by sun and moon, encircled by celestial spheres, and furnished for the great drama of man’s fall and redemption—this belief was itself the firm center of all human belief. It seemed impossible to move it without bringing down in ruin that whole grand scheme of things to which man had been fitting himself for centuries, and where he had at length come to feel himself at home. How shall one find a place for God, and a place for man, and how shall they find one another, in a universe with neither beginning nor end, neither center nor boundaries? This was the problem to which the great martyr Bruno devoted himself, and his death in 1600 may well serve as a monument to mark the beginning of modern philosophy.
Bruno saw that the world can no longer be divided into terrestrial and celestial regions, with the empyrean beyond. There can be no God above nature, or before or after nature, because nature itself is infinite. The universe is a system of countless worlds, none more divine than the rest. God is therefore not local, but universal; he is the life and beauty of the whole. This idea, recovered by Bruno from Stoicism and Neo-Platonism, and appropriated to the needs of the age which Copernicus had robbed of its ancient landmarks, persisted in the latent pantheism of Descartes and his followers, and in the avowed pantheism of Spinoza, was suffered to lapse during the eighteenth century, was revived again by Lessing 3 and Herder, and became one of the central ideas of the great Romantic and Hegelian movements in Germany in the nineteenth century.
THE CONTRIBUTION OF GALILEO
Copernicus contributed to modern thought an epoch-making hypothesis. Galileo contributed something less definite, but even more germinal—a new method. It would be safer to say that he represented two methods, the method of discovery, and the method of exact or mathematical description. He was neither the only discoverer of his age nor the only mathematical physicist, but he was the preeminent embodiment of both of these moving ideas.
In 1610, a year or so after the construction of his telescope, Galileo published his “Sidereal Messenger,” “announcing,” to quote from the title-page, “great and very wonderful spectacles, and offering them to the consideration of every one, but especially of philosophers and astronomers; which have been observed by Galileo Galilei … by the assistance of a perspective glass lately invented by him; namely, in the face of the moon, in innumerable fixed stars in the milky-way, in nebulous stars, but especially in four planets which revolve round Jupiter at different intervals and periods with a wonderful celerity.” This is the Galileo of the telescope, the prophet of an age of discovery. But greater than the Galileo of the telescope is the Galileo who formulated the three laws of motion, and so became the founder of the modern science of dynamics. He explained the fall of bodies to the earth, not by ascribing them to a vague force of gravity, but by formulating exact mathematical ratios of time and distance, so that it was possible to deduce, predict and prove, with quantitative exactness. In other words he brought the clearness and certainty of mathematics into the field of physical events.
Now this twofold influence of Galileo is the most important source of what is new in modern philosophy. Bacon and Locke were philosophical observers, trusting sense above reason, and animated by the spirit of discovery. Descartes, Hobbes, and Spinoza were mathematical philosophers, advocates of reason, not so much concerned at first to widen knowledge as to make it more certain.
Bacon (1561–1626) was the founder of modern “empiricism,” or the philosophy of sense-experience. He criticized those faults of his age that he thought stood in the way of clear seeing, such faults as verbalism, anthropomorphism, or undue regard for tradition and authority. He formulated a new “Organon” (“Novum Organum” 4), a logic and methodology which was to correct and supplement the Aristotelian organon, and afford a basis for scientific procedure. But Bacon was significant not so much for what he formulated as for what he prophesied. He was the first to dream that magnificent dream which has been so largely realized in the course of the last century: the dream of the progressive control of nature through the patient and self-denying study of it. The kingdom of man, the “New Atlantis,” 5 is to be founded on knowledge. “Human knowledge and human power meet in one; for where the cause is not known, the effect cannot be produced. Nature to be commanded must be obeyed; and that which in contemplation is as the cause, is in operation as the rule.” Observe nature in order that you may use nature, thus converting it into the habitation, instrument, and treasure of man. Here is the supreme maxim of our modern world, and the chief ground of its peculiar confidence and hopefulness.
Descartes and Hobbes were the founders of modern rationalism, but each in a different way. Descartes (1596–1650) found mathematics a model of procedure. In other words, he proposed that men should philosophize after the manner of mathematics. He did not believe that mathematics, with its applications to physics, was itself the highest knowledge. He sought rather to formulate a logic that should be as exact as mathematics, but more fundamental and universal; thus affording a basis for the demonstration of the higher truths concerning God and the soul. The “Discourse on Method” 6 is a record of the author’s profound regard for mathematics and of his own search for a like certainty in philosophy.
But Hobbes (1588–1679) was a follower of Galileo in a different sense. He proposed not so much to imitate mathematics as to adopt and extend it. He represents that idea which La Place so eloquently proclaimed a century later, and which the work of Newton seemed so nearly to realize, the idea of a universal mechanism, in which the laws of bodily motion should apply even to the origins of nature and to man. It was hoped thus to bring it about that all things should be as demonstrably known, and as certainly predictable, as the velocities and orbits of the planets. To this end the author of “The Leviathan” 7 regards both man and society, the little man and the giant composite man, as simply delicate and complicated mechanisms, moved by an impulse of self-seeking.
These, then, are the three forms in which the science of the Renaissance as embodied in Galileo is communicated to modern philosophy. Bacon, Descartes, and Hobbes became in turn the sources of the new tendencies that make up the philosophy of the seventeenth and eighteenth centuries. The empiricism of Bacon was renewed in Locke, 8 who applied “the plain historical method” to the study of the human mind; continued by Berkeley, 9 who reduced even being to perception (“esse est, percipi”); was brought to a sceptical crisis in Hume; 10 but persisted as the national philosophy of England. The rationalism of Descartes afforded a basis for the great metaphysical systems of Continental philosophy, for the monism of Spinoza and the pluralism of Leibnitz; was degraded to a mere formalism and dogmatism in Wolff; but nevertheless persisted in the new idealistic German philosophy which was inspired by Kant. The physical philosophy of Hobbes, mingled with similar elements drawn from the philosophies of Locke and Descartes, developed into the French materialistic movement which attended the outbreak of the Revolution, and remains the model for all philosophers who seek to make a metaphysics out of physics. The forms which these three tendencies assumed during the eighteenth century, and especially their excessive emphasis on facts and necessities, provoked the great reaction which bore fruit in the following century, but which was already anticipated in Pascal’s philosophy of faith, in Rousseau’s philosophy of feeling, and in Lessing’s philosophy of development.