Immanuel Kant, presented with the extreme empiricism of Hume and the extreme rationalism of Liebniz, which he discovered through the writings Wolff, sought to take a middle road between these two extreme philosophical positions. I would submit that Kant’s synthesis of these two views leads to an agnosticism about what Kant called “the thing-in-itself”, and ultimately to the philosophical positions known as Atheism, determinism, and nihilism.
First of all, Kant was influenced by Hume’s empiricism and Newton’s physics. He saw that the physical sciences, in contrast to rationalistic metaphysics, were actually making advances. They were making discoveries, and building a system of knowledge that accurately described the world of our sense perceptions. Rationalistic metaphysics, on the other hand, was floundering amidst the combating systems that the philosophers were erecting. It did not provide new knowledge, and only led to unacceptable conclusions, such as the Absolute Monism of Spinoza. Kant was also influenced by Hume’s arguments against rationalistic metaphysics by which he seemed to show that we could not build universal laws which could explain all of the events of the world of our sense perceptions prior to any knowledge of this world. Hume also argued that many of the doctrines held by the rationalists (such as the existence of God, that man has a soul, the unity of the soul, the unity of the world, human freedom, substances, universals, etc.) could not be observed in experience – our sense perceptions reveal to our imagination none of these phenomena. These doctrines were, rather, the creation of the imagination by which the knower imposed these doctrines on reality in order to make sense of what the knower’s sense impressions conveyed to the knower.
From Wolffian rationalism Kant maintained that there are some a priori principles, and that the knower is active in the knowing process. He also maintained Wolff’s three part division of the sciences. Further, Kant continued to hold two claims, as most philosophers since Descartes also maintained, first of all, that the direct object of the knower is the idea; and secondly, that our system must be built upon clear and distinct ideas – a priori first principles.
Kant, desiring to keep the best of both Empiricism and Rationalism, postulated that the senses transmit to the intellect the object that is to be understood by the faculty of the understanding. Using the well-known philosophical terms, form and matter, Kant claims that our perceptions, which are representations of the sensations, bring to the knower the matter, which is plugged into, so to say, the a priori forms of the understanding. Kant claimed that the forms, in the mind before any experience is brought to the knower, can be known by the knower without the matter of experience, and, therefore, he embarked on a detailed analysis of these forms.
Sense data – sound, colour, taste, touch, etc. – are transmitted to, and organized by, the a priori forms of the understanding. The senses give us no universal, unchanging, necessary knowledge; however, that does not mean, as Hume assumed, that due to this fact there is neither universality, nor necessity. Such things are provided, according to Kant, a priori, by the understanding.
What this all comes down to, is the idea that we cannot know anything about the mind-exterior reality, the things as they really are. We can only know the phenomenal world, and that world is neither totally independent from the knower, nor entirely the creation of the knower. The phenomenal world is a combination of sense perceptions as they are organized by the a priori categories of the knower. This unity of sensation (intuition) and understanding is what forges the world that we think we know. Therefore, as Kant would say, sensation (intuition) without conceptions (the a priori forms of the understanding) is blind, and the conceptions without the intuitions are void. According to Kant, in order for us to know the phenomenal world, the sensations and the conceptions must be united in a synthesis.
Therefore, the genius of Kant is that his synthesis of the claims of the empiricist, with the claims of the rationalist, is really and truly, a synthesis of what they each claim is the foundational starting place of all knowledge. Kant combines sense impressions with a priori principles of the understanding and gives us on a phenomenal platter Newton’s physical world, the world of the scientist.
Of course, if Kant is right, and we have seen this coming since Descartes proclaimed that the idea was the direct object of the knower, then we cannot know reality – the things as they really are. We only know our synthetic world, the world of the phenomena as it is organized by the a priori categories of the understanding.
Agnosticism and Beyond
Hume had placed a number of metaphysical doctrines outside of the grasp of the human intellect. His reasoning for doing this was that these things were not given to us by the sense impressions, but were applied to the ideas that were formed from the sense impressions as a convenient way of making sense of the world. Among these concepts were: the existence of God, immortality, the unity of the soul, the unity of the world, causality, the doctrine of substance, etc.
Kant, however, realized that some of these things, though they were not given by the sense impressions, were necessary for science, such as causality, the unity of the soul, and the unity of the world. It is, perhaps, in part, to save Newtonian science, that his theory was born. With his theory he was able to explain why, even though we are not given causality in our sense impressions, we cannot simply abandon the concept of causality. Causality is a concept that is vitally important to the advancement of scientific inquiry.
However, the existence of God, immortality, and free-will, were neither necessary for saving science, nor for “understanding” our phenomenal world, therefore, they were relegated to the world of the noumena, which was beyond the capabilities of our understanding. Neither present to our senses, nor in our understanding, there is absolutely no way to have knowledge of these concepts; and when we try to talk about them we only end up in the contradictions of the antinomies. Therefore, whether or not they exist, we can neither know them, nor talk about them. Therefore, Kant’s philosophy, his synthesis of Empiricism and Rationalism, leads inevitably to agnosticism about the existence of God, the immortality of the soul, and human free-will. If there is no sign of these things in the phenomenal world, the only world that we know, then how can we even know that they are in the noumenal world? As such, Kant’s synthesis leads not only to agnosticism about these ideas, but to a total rejection of these ideas, and therefore, to Atheism, determinism, and, essentially, nihilism.