Immanuel Kant’s Pre-Critical and Critical Philosophy
Immanuel Kant’s Pre-Critical Philosophy
Physics: Forces, Space, and Time
The physics problem during this period was the problem of forces, contrasting the defending Cartesian identification of the body with extension (space). Leibniz identified the monad with a living force, asserting that space, or extent, was merely the result of the activity of the monads. Kant attempted a synthesis of Newton and Leibniz in his first book.
This period also addressed the second major problem of physics: space and time. Newton had spoken of an infinite and absolute space (and time). Kant, following Leibniz, argued that space is relative. He admitted that space is objective and relative, and that its structure is arbitrary. He established a hypothesis about the origin of the universe that anticipates the later theory of Laplace. Finally, he raised another problem: the need to separate mathematics and metaphysics.
Metaphysics: The Challenge to Rationalism
The attacks of the Wolffian Crusius were devastating, and many thinkers began to doubt the safety of the mathematical-rationalist method. They were no longer so convinced that it was possible to “prove everything,” or that it was possible to construct an all-encompassing metaphysical system. It is in this situation that Kant’s philosophy emerges. His writings show that he was never truly a Wolffian.
Key Philosophical Developments (1764–1770)
- 1764: Kant writes Research on the Clarity of the Principles of Natural Theology and Morality, which states that the methods of mathematics and philosophy are different, but both sciences can achieve the same degree of evidence.
- 1765: He compares the metaphysics of Wolff and Crusius with the views of the Swedish mystic Swedenborg. He claims that metaphysics must know “if its goal is in proportion to its means.” Kant read Hume and began to see that any metaphysics must start with a critical examination of reason.
- 1770: In a letter, he distinguishes between a world of sense and an intelligible world, including sensitive knowledge and intellectual knowledge. This distinction was kept almost unchanged in the Critique of Pure Reason. The form of the sensible world consists of space and time. But space is not objective nor real, neither substance nor accident, nor relationship, but subjective and ideal, which comes from the mind, acting as a stable law and a coordinating scheme of all external sense.
The Critical Period: Defining Metaphysics
The Critical Period focuses intensely on the problem of metaphysics. The central question is: “If ever, and with general consent, a metaphysical state can finally reach something that is science.” This approach means that Kant simultaneously questioned the limits (against dogmatism) and the opportunities (against skepticism) of reason. This is the foundation of the transcendental or critical method.
The Central Question: What Can I Know?
This is the theme of The Critique of Pure Reason and Prolegomena. The title of the Prolegomena clearly implies the problem: Can metaphysics become science?
Kant starts from a fact: mathematics and physical sciences are sciences. Metaphysics, however, has to start by wondering if it is one. The fundamental question is how they are possible.
The Nature of Metaphysical Knowledge
For Kant, metaphysics means the same as it was understood at the time: a knowledge whose principles should never be taken from experience. Metaphysics deals with non-empirical objects (God, soul, world as a whole) and is built by pure reason, meaning it does not use any empirical data.
Opposing Views and Kant’s Critical Method
Kant identified two primary opposing positions:
- Dogmatism:
- Kant defines it as the pure intention to move forward with conceptual knowledge in accordance with certain principles without having examined the right way or the reason that leads to them.
- Skepticism:
- Reading Hume forced Kant to abandon his initial dogmatism. Hume is accused of having gone too far or having mistaken the way: for Hume, causal connection is simply a psychological habit, and therefore, the necessity of such a connection is reduced to a subjective, not objective, need. Consequently, for Hume, metaphysics is not only impossible, but even physical laws are likely to become mere probabilities.
The Path of Kant’s New Philosophy
The critical method, as Kant himself states, is the science of limits. It is a science that deals with the possibility of any science in general, and metaphysics in particular.