While philosophers kept busy thinking and writing, the world was changing.
From the late 18th century, there were incredible changes in the world. Revolutions were abounding, changing the basic structure of the world as it was known. The American Revolution, the French Revolution, and the Industrial Revolution were only three of these. From this time, philosophy took so many twists and turns that it cannot be categorized into any specific approach. Plato, Aristotle, and others were mostly seen from a more practical perspective. Metaphysics lost its popularity in this new world of increased skepticism. After 1500 philosophy found itself in a world of growing population, new inventions, and the denial of the metaphysical as an rationalization of reality.
During the Renaissance a obsession with mathematics and science began and lasted for the next two hundred years.
Early in the modern period Francis Bacon was an zealous teacher of new learning. He theorized that knowledge cannot be based on accepted authorities but must begin with experience and proceed by introduction to general ideas. He was the basis for early British empiricism, one of the main schools of modern philosophy.
Modern rationalism originated with the work of René Descartes. From the declaration, "I think, therefore I am," Descartes continued to create a system in which belief in God and the mind belong to one order of reality and the outside world to another. He viewed nature as a device that can be explained mathematically, and viewed God as pure spirit. The reconciliation of these two facets of reality engaged many other philosophers, including Nicholas de Malebranche, Baruch Spinoza, and Gottfried Wilhelm Leibniz.
While rationalism was taking hold on the European mainland, empiricism gained popularity in England. The foremost empiricists were Thomas Hobbes, John Locke, George Berkeley, and David Hume. They were mainly interested in the mind's processes.
It was Hume's uncompromising skepticism that led Immanuel Kant in Germany to launch a brilliant, but unsuccessful, attack on it in his 'Critique of Pure Reason'. In it he deals with reason and its potential and limits. In 'Critique of Practical Reason' he examines ethics, and in 'Critique of Judgment' he investigated aesthetics. Kant is another of the giants of Western thought, and his influence endured in the work of the German idealists Johann Gottlieb Fichte, Friedrich Schelling, and Georg Wilhelm Friedrich Hegel.