d. All rational beings think the world in terms of space, time, and categories such as cause and effect, substance, unity, plurality, necessity, possibility, and reality. That is, whenever we think about anything, we have to think about it in certain ways (for example, as having causes, as existing or not existing, as being one thing or many things, as being real or imaginary, as being something that has to exist or doesn't have to exist), not because that is the way the world is, but rather because that is the way that our minds order experience. There can be no knowledge without sensation, but sense data cannot alone provide knowledge either. We can be said to know things about the world, then, not because we somehow step outside of our minds to compare what we experience with some reality outside of it, but rather because the world we know is always already organized according to a certain fixed (innate) pattern that is the mind. Knowledge is possible because it is about how things appear to us, not about how things are in themselves. Reason provides the structure or form of what we know, and the senses provide the content. Many other philosophers, mainly empiricists, disagree with Kant’s ideas. One major objection is that we can never know anything about things we do not experience and organize in terms of the mind's structure. For example, we could never know anything about God, soul, and other metaphysical topics. Kant's solution means that we will never know if our ideas about the world are true; or it means that we have to “redefine reality as that which we experience rather than that which experience represents.” In short, if we are limited to phenomena (things as they appear), either we will never know if our ideas are true or we have to redefine what truth is. If Kant is right, then why do cultures seem to differ on the categories of understanding? One possible answer is that even though the categories seem...
