The following lectures discuss the similarities and differences between the rationalists philosophers of the 17th century (Descartes, Spinoza, and Leibniz) and the empiricists philosophers, J. Locke and D. Hume, which vivid disputes have inspired one of the most important philosophers of all times, Immanuel Kant, and his unavoidable critique of Metaphysics.
The philosophy of Immanuel Kant offers a great philosophical synthesis between rationalism and empiricism, but also sets a tone for the whole of modern Philosophy; if metaphysics is not possible, then what is the meaning of philosophy? Is there any meaning at all?
The philosophy of David Hume woke-up Immanuel Kant from the “dogmatic slumber” in that “Matters of Fact” often do not correspond with the “Relations of Ideas.” Considering the matters of fact, how is it possible that the scientific truth could contradict the common sense experience? The sun rises from the East and sets in the West. It then seems that the sun circles the Earth, but science proves that’s not the case. Conversely, considering the relations of ideas, why can’t the metaphysical models be proven as absolute truths?
According to Hume, the “Matter of Fact” are explainable only by the cause and effect reasoning, which implies that truths we know are ultimately verified through the experience, and therefore all knowledge about the world–matter of fact, and ideas, are both a-posteriori. What would be knowledge about the world or relations of ideas based on the a-priori knowledge, not based on experience but on reason alone? Hume concludes that this type of knowledge is not possible due to the causality that sets final judgments on what it is and what is not. To understand the world that it is, and the world that is possible rather then the one that is not, and is not possible, is to know the limitations of the mind.
Kant seriously takes Hume’s sharp discovery and “cuts out” the Philosophical pretension that Philosophy can attain knowledge of the true nature of reality as such. His “The Critique of Pure Reason” results in analyzing the unbridgeable antinomies of human reason and the Copernican revolution in epistemology, where by which the representational theory of knowledge is defeated. According to Kant, humanity as a species creates the object of knowledge, and the object of knowledge conforms to the acquisitions of the human mind. This mind is rooted on the a-priori conditions of all knowledge for every human being; time, which the vessel is one’s self-active consciousness, and the space, which displays reality in three-dimensional design.
“Thins as objects of our senses existing outside us are given, but we know nothing of what they may be in themselves, knowing only their appearances, i.e., the representations which they cause in us by affecting our senses. Consequently, I grant by all means that there are bodies without us, that is, things which, though quite unknown to us as to what they are in themselves, we yet know by the representations which their influence on our sensibility procures us, and which we call bodies. This word merely means the appearance of the thing, which is unknown to us but is not therefore less real.” Immanel Kant, Critique of Pure Reason, trans. Norman Kemp Smith. New York: St. Martin’s Press, 1956. pg. 33
Instead possibility to know the reality in a form of substance, Kant offers a solution to this problem in that the noumenal, purposive, world sits in “the Kingdom of Ends,” the self-imposed morality that one achieves through intentions that become rational, and therefore, the source of the inner growth and enlightenment. This kingdom is an inborn compass chained to free will.
“Freedom is certainly not lawless, even though it is not a property of will in accordance with laws of nature. It must, rather, be a causality in accordance with immutable laws, which, to be sure, is of a special kind… (….) What else, then, can freedom of the will be but autonomy, i.e., the property that the will has of being a law to itself? The proposition that the will is in every action a law to itself expresses, however, nothing but the principle of acting according to no other maxim than that which can at the same time have itself as a universal law for this object. Now this is precisely the formula of the categorical imperative and is the principle of morality. Thus a free will and a will subject to moral laws are one and the same.” Immanuel Kant, Grounding for the Metaphysics of Morals,” trans. James W. Elington. Indianapolis: Hackett Publishing Co., 1981.
With I. Kant’s move from the first critique, “The Critique of Pure Reason” to his second critique, “The Critique of Practical Reason,” the history of philosophy shifts from speculative rationality to the ultimate question of human responsibility in response to the world that faces changes (growth of scientific knowledge) and historical crises (political struggle, wars, recognition of a dignified human being).
The crisis imposed by the revolutionary times of 18 century could be resolved, according to Kant, only and only through Philosophy. The necessary condition of new Philosophy is in accepting human freedom as a rational form that defines one’s personality. Only a free human being is a dignified person, and only a dignified person knows truth in acting rationally while expressing free will through the self-imposed principles crowned in one’s intentional actions.
“Reason must regard itself as the author of its principles independent of foreign influences. Therefore as practical reason or as the will of a rational being must reason regard itself as free.” Immanuel Kant, Grounding for the Metaphysics of Morals,” trans. James W. Elington. Indianapolis: Hackett Publishing Co., 1981.
While the speculative metaphysical models of dualism (Descartes), monism (Spinoza), and pluralism (Leibniz) seem to be “the castles in the air” to the empiricists who argue that the highest ideas of God, soul, and freedom are subject to the human knowledge limitations, Immanuel Kant calls for a new turn in the history of Philosophy.
Whilst the a-priori conditions of all knowledge project the representations (phenomena) of the world as real, according to Kant, the noumenal world, the “Kingdom of Ends,” resides in moral universal laws that are a part of human nature and intuition.
Here are some inspiring quotes from Immanuel Kant’s philosophical work:
“Whatever concept one may hold, from a metaphysical point of view, concerning the freedom of the will, certainly its appearances, which are human actions, like every other natural event are determined by universal laws. However obscure their causes, history, which is concerned with narrating these appearances, permits us to hope that if we attend to the play of freedom of the human will in the large, we may be able to discern a regular movement in it, and that what seems complex and chaotic in the single individual may be seen from the standpoint of the human race as a whole to be a steady and progressive though slow evolution of its original endowment.” Idea for a Universal History from a Cosmopolitan Point of View (1784). Translation by Lewis White Beck. From Immanuel Kant, “On History,” The Bobbs-Merrill Co., 1963.
Immanuel Kant on Enlightenment: “Enlightenment is man’s release from his self-incurred tutelage. Tutelage is man’s inability to make use of his understanding without direction from another. Self-incurred is this tutelage when its cause lies not in lack of reason but in lack of resolution and courage to use it without direction from another. Sapere aude! “Have courage to use your own reason!” – that is the motto of enlightenment. “What is Enlightenment? (1784)
by Immanuel Kant, translated by Lewis White Beck.
The Copernican Revolution in Epistemology: Immanuel Kant
Rationalism, Empiricism, David Hume: Matters of facts often do not correspond to the concepts and ideas!
More closely the Rationalists, Spinoza and Leibniz
Leibniz and Monadology: Metaphysical Pluralism
Baruch de Spinoza: “Deus Sive Natura” and Metaphysical Monism