If Kant's claim that we can only know the world as it appears to us (rather than as it really is in itself) turns out to be true, what does that mean the objects of our claims about knowledge are? Can knowledge still be universal? What if we don't all possess the same categories?
One could certainly argue that there are universal truths to which all mankind can agree. Basic immutable facts, such as the laws of physics, allow for a definite amount of certitude regarding the structure of the universe, and that’s not nothing. In the preface to the first edition of his Critique of Pure Reason, Immanuel Kant wrote that “As regards certitude, I have fully convinced myself that, in this sphere of thought, opinion is perfectly inadmissible, and that everything which bears the least semblance of an hypothesis must be excluded, as of no value in such discussions.” Laws of physics may have begun as hypotheses, but, once proven, they emerged as knowledge. In short, cultural and historical differences do not undermine the validity of this knowledge. Perceptual distinctions disappear in the world of science, although such distinctions do not eliminate the differing paths to knowledge that may be taken and that influence methodologies.
Once knowledge derived through scientific exploration is exhausted, the rest is all a matter of perception and speculation. Students of international affairs are taught the vital distinctions between perceptions of reality that dominate exchanges between nations and governments. To the Chinese, who endured many years of European colonization only to be brutally occupied by Japan during the 1930s, the American presence in the South China Sea is just one more example of Western imperialism intruding on its natural sphere of influence; to the United States, the Chinese quest to dominate that vast region is an example of a growing and increasingly aggressive Chinese foreign policy intended to deny natural resources to other nations. During the Cold War, many American strategists and analysts of the Soviet Union viewed Russian assertiveness through the prism of great power politics; to the Soviet Union’s leadership, the American military presence in Western Europe and American policies intended to “roll back” Soviet expansionism were threatening in the same vein as the Napoleonic and German invasions of Russia. Each side viewed the other’s actions through its own historical and cultural prisms. In other words, alternate versions of reality defined the bipolar world structure that existed from 1945 to 1989.
“Knowledge” can be considered the accumulation of experience and observations, but that is not necessarily the same as “truth.” Objective reality is limited to what can be scientifically proven, unless, of course, one’s perception of reality is influenced by the role of faith. Perceptions of reality shaped by Biblical prophesies are as real to many as they are derided as fantastical by others. Debates regarding evolution and Creationism are heavily informed by these fundamental distinctions between those who “believe” and those who reject that which cannot be independently verified.
Now, this represents the perception of one “educator,” who is no one’s idea of a philosopher. The student can easily cite Kant’s approach to the notion of “objective fact” in his Critique of Pure Reason, in which he wrote:
“How is pure mathematical science possible? How is pure natural science possible? Respecting these sciences, as they do certainly exist, it may with propriety be asked, how they are possible?—for that they must be possible is shown by the fact of their really existing. But as to metaphysics, the miserable progress it has hitherto made, and the fact that of no one system yet brought forward, far as regards its true aim, can it be said that this science really exists, leaves any one at liberty to doubt with reason the very possibility of its existence.”
This passage represents philosophy at its finest. How do we know we exist? It’s entirely up to the individual to decide what he or she thinks regarding abstract concepts that question existence. The late United States Senator Daniel Patrick Moynihan once remarked that “everyone is entitled to his own opinion, but not to his own facts.” If philosophers are correct that universal facts are impossible to confirm, then even the esteemed senator’s observation is invalid. Personally, this educator will stick with the notion that objective realities do exist, if only because mathematical precision allows for verifiable claims of fact. But, then, I did get a “D” in Introduction to Philosophy 101.