Kant's View on Science and Metaphysics

Kant on Scientific Knowledge and Metaphysics

In the Critique of Pure Reason, Kant is concerned with determining the problem of knowledge and analyzing the possibility of metaphysics as a science, with the same rigor and accuracy that mathematics and physics had achieved at that time.

Kant understood metaphysics as the discipline inherited from previous philosophical traditions (such as medieval scholasticism or the rationalist school). It was considered the foundation and basis not only of all sciences but also of values, morality, politics, etc.

Rationalism vs. Empiricism

Rationalists believed that the mind could know reality without the help of experience; the mind possessed innate principles.

On the other hand, empiricists believed that all knowledge came from experience. They considered rationalism to be simple charlatanism that had no basis independent of experience. Metaphysics fell into general contempt, which worried Kant, because although metaphysics was not a science, it dealt with the most important questions for human beings, which, although they did not have a scientific answer, were nonetheless crucial.

Why Metaphysics Lags Behind Science

According to Kant, mathematics and physics had entered the secure path of science, but metaphysics had not, for the following reasons:

• Lack of Unanimity: In physics, all scientists agree on the theory, but disagreement reigns in metaphysics. Worst of all, there is no criterion to know which theories are true and which are not.
• Stagnation: While other sciences advanced, metaphysics remained stagnant, as no one could agree.

Kant asked about the possibility of metaphysics as a science, but he also had to wonder how science itself was possible.

Kant does not question whether science is true or not, because for him it is clear that it is. What he wants to know is why it is true. He wants to identify the elements that form scientific knowledge to compare them with metaphysics, and to see if metaphysics, by possessing these elements, could someday come to be regarded as a science, or not.

Kant will submit metaphysics to the court of criticism, understanding criticism as a "rational analysis or examination." Reason analyzes itself to know its limits. The problem of metaphysics is that it has not rectified its own principles after a rational analysis.

Hume's Skepticism and Kant's Response

However, empiricism, by rejecting nativism and arguing that all knowledge comes from experience, leads to skepticism. David Hume concluded that since he could not prove the existence of God, he could not demonstrate the relationship between thoughts and reality. Even scientific laws were not safe. If these laws are mere generalizations from experience, and experience is contingent and particular, nothing assures us that natural phenomena will always behave the same way in all cases. Hume concluded that we must admit that reason is unable to provide a foundation for knowledge, so that instead of seeking an absolute or metaphysical certainty for knowledge, we must be content with a moral certainty sufficient to guide us in our daily lives.

For Kant, only that which contains necessity (that is necessarily so and cannot be otherwise) and universality (which always happens or acts the same way) can ensure reliable knowledge. Either scientific laws are universal and express the existence of a necessary connection in nature, or they are not scientific laws.

The rationalists said that experience was good for nothing, and empiricists said that everything came from experience. But for Kant, both had a point, because experience is necessary for knowledge, but not sufficient. Knowledge also requires conditions independent of experience, which are what provide the notes of universality and necessity.

Rationalism had argued that reason possessed a number of innate principles and that, from these principles, by rational deduction, without recourse to sensory experience, one could build the edifice of knowledge and know the real in its entirety.