Immanuel Kant (1724-1804) is the foremost and central figure in western philosophy. His greatest work Critique of Pure Reason stands out as one of the most influential philosophical treatise of all times. In the coming series, I am planning to record notes which I find important (and interesting) when trying to understand Kantian philosophy.
A small note on Kant's view on his days which I thought was interesting. It appears Kant did not enjoy his youthful days. He says:
Many people imagine that the years of their youth are the pleasantest and best of their lives; but it is not really so. They are the most troublesome; for we are then under strict discipline, can seldom choose our friends, and still more seldom have our freedom.
Now on to philosophy. There were at least two outstanding questions related to metaphysics which led Kant to formulate his philosophy. One was Descartes famous cogito ergo sum (I think, therefore I am) and the other was the antagonism between Leibniz's rationalism and Hume's empiricism.
cogito ergo sum
According to Descartes it is senseless to doubt our existence. The fact that we can think of our existence means that we exist, for sure. Roger Scruton1 remarks "here doubt only confirms what is doubted". However, critical analysis of cogito ergo sum reveals our existence is not vouched by that statement, but rather a thought exists about our existence. cogito acknowledges there is a thought and ergo sum acknowledges our existence. But even when taken together it doesn't mean "I" exists but rather a thought that "I exist". Thus, when Kant was framing his thesis, there was no argument that was readily available to affirm or deny the existence of "I".
Leibniz's Rationalism
Rationalism is a philosophy that emphasizes that all knowledge is derived primarily from reason and claims to provide an absolute description of the world that is independent of observers experience. Leibniz belonged to rationalist school of thought in which he described the world consisting of infinitely many individual monads each of which living eternally outside space and time. Each monad has a view of reality but ultimate reality is inaccessible to any monad through experience although it can only be realized through reason. Such a reality is more like a surface defined by function of several variables, where each variable is a monad. And experience of reality for a particular monad can be imagined as a restriction of other variables to a constant, during which a section of reality, and not the whole, can be described.
Hume's Empiricism
In contrast to Leibniz, Hume was a empiricist. Empiricism is a philosophy that believes all forms of knowledge are a product of experience and not reason. We gather information only through the senses and so there is no reason to believe reason can alone derive any knowledge. Far from it, it is only through experience all knowledge are gathered. There is no such thing as monad or soul, because experience doesn't tell us if there are any. Also rationalists claims of ultimate description of the world accessible only through pure reason are false since they run contrary to sense perceptions. There could be no single description of the objective universe. Everyone has their view of the world which gets superposed thorough relations. On other words, relationships of experiences only define the objective world and nothing else.
Hume's empiricism and especially this extreme skepticism was unacceptable to Kant and he noted Hume woke him up from "dogmatic slumbers". Roger Scruton1 notes:
Kant did indeed have a lasting quarrel with Leibniz and with the Leibnizian system. But it was the sense that the problems of objectivity and that of causal necessity are ultimately connected that led him towards the outlook of the Critique of Pure Reason. It was only then that he perceived what was really wrong with Leibniz, through his attempt to show what was really wrong with Hume.
References
1. Roger Scruton, Kant: A Very Short Introduction, Oxford University Press; Revised edition December 6, 2001.
