IV Modern Philosophy

Modern philosophy began with Rene Descartes. He was the first philosopher to throw out all unquestioned assumptions and proceed, by means of a powerful, rigorous deductive method (derived from mathematics), to construct a universe ruled by rigid laws of cause and effect. This view of the world as a deductive system was shared by the other great rationalists of the same period, Spinoza and Leibniz. But a problem arose from this view: since humanity is part of this orderly world, it would seem that our actions are, like all other events, determined--not free.

On the other hand, the Bristish empiricists-Locke, Berkeley, and Hume-rejected the rationalists' deductive approach in favor of the inductive point of view, that we can know only what we learn through sensory experience--what we see, hear, smell, taste, and feel. But with Hume this philosophy was taken to its logical extreme and we are left with a meaningless "parade of sensation,"

So the rationalists were saddled with the problem of freedom, and the empiricists were faced with a radical skepticism. And then came the great German philosopher, Kant, who offered a solution to both problems. It is true, Kant said, that all knowledge must begin with sensory experience; but that experience is given shape by the mind and its structure-so we are able to know more than just a parade of sensations. And although the self lies outside our sensory experience, we must presume that it is free-- otherwise our moral judgments would make no sense.

Although Kant had solved the problems of his philosophical predecessors, he had introduced the revolutionary idea that the mind gives the world its structure. The only world we can know about, he said, is the "phenomenal" world-the world as filtered through our mental apparatus, our concepts and categories. Though Kant believed in an external, "noumenal" world, a world of things- in -themselves, he held that we cannot know anything about that world.

So Hegel, the great German idealist, proposed that we drop the notion of this "external world" entirely; and so the world becomes totally the product of mind! But the mind goes by certain rules, the rules of dialectic-- the mind has an idea, which calls forth its opposite, and idea and opposite are reconciled into a synthesis, which in turn calls forth its opposite, and so on. Hegel tried to explain all of history and reality in terms of this dialectical process. His thought dominated the rest of the nineteenth century.

Still this idealism leaves the world as a kind of ghostly product of mind. So Marx submitted a slight revision. What's real, he said, is matter. Then he went on to explain history in dialectical--but materialistic--terms. And a reaction to Hegel's overpowering intellectual system set in immediately in the philosophies of Shopenhauer, Kierkegaard and Nietzsche. Kierkegaard's ideas, though ignored during his lifetime, flowered in the Twentieth century with the work of the existentialists.

Meanwhile, in England, Bentham and Mill carried empiricism in the direction of the ethical-political philosophy of utilitarianism. And in America Peirce and James were developing the philosophy of pragmatism.