This may not exactly sound like a call to arms, but being called an expert and having an interesting new encounter with a philosopher encourages us to think differently. Markus Willaschek's Kant: A Revolution in Thought (Harvard), translated by Peter Lewis, argues that what made Kant revolutionary was his claim that in order to understand anything—science, justice, freedom, God—we must first understand ourselves. Willaschek, one of the world's leading scholars of Kant and editor of the standard German edition of Kant's works, writes: “Kant placed man at the center of his thought like no other philosopher before him.” As Willaschek shows, Kant believed that his ideas would change humanity's understanding of its place in the world as profoundly as the Copernican revolution changed our understanding of the Earth's place in the cosmos.
And they did, at least for philosophy, ushering in the most fruitful period in Western thought since Plato and Aristotle. Willaschek suggests assessing Kant's influence by looking at the term “critique,” which Kant used in the titles of three of his major books: Critique of Pure Reason (1781), Critique of Practical Reason (1788), and Critique of Judgment (1790). At that time the word criticism was a relatively new addition to the German language, and Kant was the first to use it in a name. Today, Willaschek writes, “the catalog of the German National Library contains no less than twenty-four thousand works with the word ‘Critic’ in their titles.”
More broadly, he notes, Kant's ideas about reason shaped the development of “psychology, anthropology, and the latest social sciences.” In the twentieth century, philosophers of science encountered Kant as they tried to make sense of the puzzling discoveries of relativity and quantum physics. The American Transcendentalists took their name from one of Kant's key technical terms: “I apply the term transcendental,” he wrote, “to all knowledge which is concerned not so much with objects as with the way in which we know those objects.” Thus, Ralph Waldo Emerson expanded on Kantianism when he declared: “I become a transparent eyeball; I am nothing; I see everything.”
The central insight that these different thinkers borrowed from Kant is that the world is not just a thing or a collection of things given to us to perceive. Rather, our minds help create the reality we experience. In particular, Kant argued that time, space and causality, which we usually take for granted as the most basic aspects of the world, are better understood as forms. imposed on the world with the human mind.
The parallel with Copernicus turns out to be apt. Before Copernicus, Kepler and Galileo, people assumed that the Sun and planets revolved around the Earth, and this is quite reasonable – this is exactly what it seems to us when we look at the sky. It took astronomers a lot of careful observation and ingenious reasoning to realize that this was a game of perspective and that it was actually the Earth that revolved around the Sun. Likewise, it is natural for people to assume that the way the world appears to us—expanded in three dimensions, constantly moving from past to future, changing as its various elements interact—is how it really is. But, Kant argued, this is also a deception of perspective. Space and time do not exist objectively, but only subjectively, as forms of our experience. He wrote that “only from the human point of view can we talk about space, extended objects, etc. d.”
This thought led Kant to a more pessimistic conclusion than that of Copernicus. Although humanity eventually came to a correct understanding of the solar system, we cannot ever know “things in themselves”—what Kant called “noumena.” We only have access to “phenomena”—how things look to us, given the type of mind we have. “What things in themselves can be, I do not know and should not know, because a thing never appears to me except as an appearance,” Kant insisted.
This is an “alarming” message, Willaschek writes: “It seems, so to speak, to strip all the things around us of their solidity and reduce them to mere figments of our imagination.” In fact, Kant did not intend to make us doubt the evidence of our senses. Instead, he reasoned, scientific knowledge is possible precisely because all people perceive the world through the same categories of time and space. Science claims to deal with the world only as we perceive it, and not as it is “in itself,” and in this sense it is quite reliable. Anyone who measures an object in free fall in a vacuum will find that it is accelerating at a rate of thirty-two feet per second squared; we don't have to worry that it's “a figment of our imagination.”
