Kant In A Nutshell
By Philip McPherson Rudisill
April 30, 2007 and last revised or edited on July 21, 2012
A draft of a summary and exposition of Kant's The Critique of Pure Reason (CPR) Groudwork to the Meataphysic of Morals (GMM), The Critique of Practical Reason (CPrR) and Religion Within The Bounds Of Bare Reason.(Religion). Later I hope to include the same for Kant's The Critique of Judgment.
Kants ultimate intention (in this writer's opinion) is the moral redemption of the world.* Accordingly he needs to validate freedom in a world of natural science.** In the CPR he finds freedom to be thinkable (but not recognizable) in sync with a world of nature.***
[* In support of this opinion I cite sentence 3.1 of the Preface to the CPrR, namely: "Now the concept of freedom, to the extent its reality is proven through an apodictic law of practical reason, constitutes the keystone of the entire edifice of a system of pure, even speculative, reason." This "apodictic law of practical reason" will be shown to be the moral law.
[** To do this he must first validate natural science (against the challenges of David Hume) essentially by explaining what Hume knew but could not figure out how he knew, namely that his table did not get smaller at a distance (though it certainly seemed to). We know that light from the sun strikes the table before us and some of that light is reflected from the table and makes an impression on our retina. This impression is changed into electrical impulses which are transmitted to the brain and there a projection arises in what we might call the brainarium. As an appearance in the brainarium (or on the retina) this table doesnt exist when we blink. Furthermore I see a tree to the left of a bush and I tend to forget that the reason that I see it to the left is because thats the way I look at things within the brainarium. Left and right are just forms of my looking. With time it is the same. I recall a memory and at the moment of picturing that memory, I look at it as earlier even though as a consciousness it is precisely now and not before. This "now and before" is also just my way of picturing or looking at appearances within the brainarium. Consequently all that the brainarium contains and can show us and all of the time and the space that we spy in our looking, are not things on their own at all, but merely modifications within our brainarium.
[The great task for Kant at this point is to show first that the objects we see are not real things on their own. If they were then we could not even imagine that the categories of our connective understanding, e.g., cause and effect, could have the least meaning and reference to them. Now we show that this understanding, our categorical connective awareness, is a product of our minds, and in this regard is like space and time. As the latter are the form of our looking, the former are the form of our connective thinking and recognizing. And since we know (per above) that what we spy are not things on their own, but just appearances within us, it makes sense that our understanding and connective capacity could have an application. And this is precisely what we do, and the result of this synthesis is the recognition with Hume that his table does not get smaller at a distance, even though it seems to, and the reason is because what we are seeing and looking at are not things, but only the appearances of objects within the brainarium. Without this we could never make the least sense out of such words as looks like or seems to be and we would be taking mere appearances to be things on their own, e.g., a shrinking table.
[This validation (called the Transcendental Deduction) is quite tedious and can serve no purpose for natural science, but it does aid in explaining how it is that pure reason stumbles so badly when it seeks to go out beyond experience and speculate about things on their own independently of the human viewer. And this will aid in the reconciliation of science and freedom cited above.]
[*** Kant will have established that the laws of nature, e.g., causation, are universally applicable and without exception. But then this would deny even the possibility of freedom. Kant now turns to the reconciliation of these laws and freedom. We know that a leaf, for example, is an object of experience and accordingly is subject to laws of nature such that when the weather turns cold and windy, the leaf is swept away from the tree in accordance with laws of nature. Now purely as an arbitrary assertion to prove a point, when we consider the leaf not as an object of experience (which is merely a composite of many appearances within the brainarium), but as a thing on its own, then we can say that the leaf was not torn away but freely chose to let go of the tree, and it was simply a coincidence that it was cold and windy. This serves no purpose in science, and does not prove even the possibility of freedom, but it does prove that it is possible for freedom and the necessity of nature to exist side by side if one wanted to assume that for some reason. All that is required for this is that one not contradict 1, the events in science nor 2. one's own thinking.]
Next (in GMM and CPrR) Kant finds that the human is conscious of the moral law as binding and motivating.*
[* The moral law is simply the requirement to universalize one's personal principles of actions (maxims) in order for a group of free beings to coexist in a society. It proves the capacity of pure reason to direct the will without any assistance from any object of desire. And since it is pure reason it is also in the possession of every rational being.]
Objective indication of this consciousness of the moral law: the willingness at an earlier time to consider a school on freedom among the sciences, which as a mere speculative idea is as just as absurd as considering a school on flying invisible unicorns. This consideration was only due to the respect which all people, including scientists, have for the moral law.
Subjective indication: the ability to distinguish the two questions of the gallows case*, and not see the latter question as absurd in light of the first. I.e., It is clear that I shall give up all pleasure for the sake of my life, so why wouldnt I give up the life of another person for my own life? Only a free being, subject to the moral law, can consider this as a real question and not a joke.
[* "Suppose that some one were to aver of his most passionate desire that it were irresistible if the alluring object and the opportunity to it were at hand; ask him whether he might not be able to master this desire if a gallows were erected before the house where he is to avail himself of this opportunity, in order that he might be hanged there immediately after his savored passion . . . it wont take long to guess his answer. But inquire of him further: suppose his sovereign, threatening him with the same inexorable death penalty, should require him to bear false witness against an upright man whom the king very much wishes to ruin through trumped up charges, and given how much his love for life might be, ask him whether he would consider it possible that he might overcome this love of life? Whether he would do it or not, he may not be able to say; but that it be possible for him to do so, this he will admit without hesitation. Therefore he judges that he can do something for the simple reason that he is aware that he ought to do so, and recognizes within himself the freedom which otherwise, without the moral law, would have remained unknown to him." (CPrR No. 6 2nd Task)]
Accordingly then the human knows that he is free. And so freedom, which was only thinkable in speculative reason, is now recognized as a fact, namely that we are indeed free, even though it remains totally inexplicable.
There needs to be a purpose to this moral law, to keep it from being considered as a troublesome vanity, and the only purpose suitable to rational beings such as the humans is the highest good, i.e., a state of moral perfection and perfect happiness on an individual level, and a degree of moral perfection and a commensurate degree of happiness on a social level. Accordingly the highest good is the necessary object of the moral law.
The only expectation for moral perfection of the human consists in a continuing advance which means a life beyond the grave. And the only expectation for a commensurate happiness is via a God.* And so both immortality and God ensue from the recognition of the highest good as a practical goal for such as the human, as the necessary conditions for that highest good.**
[* Speculative reason (in CPR) was even less successful with immortality and God than it was with freedom (which was paltry enough). And no information was gleaned in this way, except to show that it was not impossible to think both of them. But no example could be presented for these two to be applied even as fictions, as was at least the case with the assumption of freedom.]
[** It should be noted that the recognition of freedom and the postulation of the soul and God have utterly no meaning for the natural sciences since there is no way of ever obtaining any admission of these into the equations of the sciences. And so the total value of this information is in the realm of the practical and not the theoretical or speculative.]
Kant then develops a suitable religion (in Religion) to reflect this understanding of God, namely a moral and universal religion. He finds a reasonable expression of this religion in Christianity, for he finds the practical core of Christianity, when ignoring dogma and the cultural context of its beginning, to be thoroughly and uniquely moral.
See a more expanded version of this nutshell presentation.along with links to more detail expositions.