Discussions of Kant usually focus on his main philosophical ideas – empiricism, rationalism, ethics, epistemology and whatnot. These ideas place him in the front rank of modern Western philosophers (though far below the ancients, in my opinion). If we look at Kant from a different angle, however, another picture emerges.
Concerning his militarism, people who run across such statements of Kant as the following will assume he was opposed to war, a reasonable man, the epitome of the finest tendencies of rationalism: “the barbarous expedient of war”; “reason, as the highest legislative moral power, absolutely condemns war as a test of rights and sets up peace as an immediate duty”; “war, the source of all evils and moral corruption,” and so on.
It is necessary, though, to read the fine print. In so doing, we learn that war promotes “that close association of social classes within the commonwealth which promotes the well-being of all” . War stimulates social cohesion which helps towards a greater degree of freedom . Thus, “so long as human culture remains at its present stage, war is therefore an indispensable means of advancing it further” [102-03]. Peace will only be possible “when culture has reached its full development – and only God knows when that will be” .
So, war is bad, and someday we will progress beyond it, but for the present it is necessary and even beneficial. This explains Kant’s sympathy for the French revolution. True, much blood was shed in wars and massacres, but that was necessary for the progress of mankind. This idea of war as necessary and beneficial, as “natural” and part of nature’s plan was to become over the next fifty years and more one of the cornerstones of German militarism.
Kant was also a racist, and in his Physical Geography expressed his philosophical belief in the superiority of the white race.  Moreover, he presented a concept that was later to become an important justification of totalitarianism – the idea that there was more real democracy and representation of the will of the people in the rule of an enlightened despot like Frederick the Great, than there was under a parliamentary system like that of Great Britain, which (in Kant’s view) was only a swindle [81-82].
Thus, Kant could enthusiastically explain that “our age is the age of enlightenment, the century of Frederick” . The Poles were less enthusiastic about Prussian warlords furthering the progress of humanity with their enlightened wars and conquests. By “uniting the collective will of the people in his own” , the monarch derives real authority. The people don’t need democracy because their ruler represents them faithfully.
Significantly, Kant thought progress would come “from the top downwards” . The state and its enlightened leadership would guide the common people on mankind’s upward progressive path. This would require a comprehensive system of national education “designed on the considered plan and intention of the highest authority in the state” [84-85].
Concerning Kant’s anti-Semitism, there is a very interesting book called German Idealism and the Jew: The Inner Anti-Semitism of Philosophy and German Jewish Responses by Prof. Michael Mack. This book shows, convincingly I believe, how Kant helped to introduce a new kind of anti-Semitism into German Kultur. Kant was not concerned about the Jews being under God’s wrath for the crucifixion of Christ. He had no interest in such unreasonable ideas. He objected to Jews because their rigid adherence to unchanging divine laws alienated them from the progress of humanity, and isolated them from natural human feelings.
Kant also missed clear references in the Old Testament to the afterlife (Daniel 12:2-3; Psalm 23:6; Psalm 16:11; Isaiah 65: 17-18). Out of this misunderstanding, he reasoned that Jews were only materialists, interested in serving God just for the sake of material gain and earthly benefits (Genesis 28:20-21). These misguided ideas became standard themes of more radical anti-Semites who, later in the 19th century, added yet other ideas (including racial purity and hostility to Jewish-inspired Christianity) to portray Jews as an unhealthy and even dangerous cultural influence. The following quote from Mein Kampf reflects Kant’s enlightenment anti-Semitism (expressed of course by many others as well):
Due to his own original special nature, the Jew cannot possess a religious institution, if for no other reason because he lacks idealism in any form, and hence belief in a hereafter is absolutely foreign to him . . . Indeed, the Talmud is not a book to prepare a man for the hereafter, but only for a practical and profitable life in this world (Vol. I Chapter 11, “Nation and Race”).
Kant is an excellent example of the truth of that saying of Christ’s, “That which is highly esteemed with men is an abomination with God.” In the eyes of men, Kant was a brilliant philosopher, but from the biblical point of view his philosophy is folly, delusion, and a complete waste of time. If I were stranded on a desert island with nothing to read but the complete works of Kant, I would sit next to that pile of books wishing I had something to read.
It would take too long to elaborate on the many errors, misconceptions, and outright falsehoods that vitiate Kant’s philosophy and render it null and void. His beliefs that the highest cause was inaccessible to us ; that man was nothing but “a mere trifle” relative to “the omnipotence of nature” ; that mankind was on an upward course of moral progress and improvement [78-79]; that human reason was the highest source of knowledge and that human instinct was a reliable guide, and even a ‘voice of God” ; that God “will make up for our own lack of righteousness so long as our attitude is sincere” ; that it is “absurd” to claim “theoretical knowledge of the transcendental”  – these and other errors reveal a system of thought totally opposed to biblical Christianity.
Kant’s “categorical imperative,” his attempt to provide a foundation for human ethics on human reason alone, was a complete failure. For example, someone could reason: “Jews are a menace to mankind. If everyone did as I am doing and killed Jews, the world would be a better place. Therefore, killing Jews is ethical.”
Kant’s pontifications on human knowledge and perception lacked a solid foundation. If we are nothing but matter and our knowledge and perceptions are thus nothing more than chemistry and biology, or if we have immortal souls created by God and can perceive and reason as we do because we are made in the image of God, in either case Kant’s epistemological guesswork was very wide of the mark, superfluous, and irrelevant.
Someone who spent one year diligently studying Kant in the pursuit of wisdom would at the end of that year be farther from his goal than he was when he started. At best, a brief examination of Kant can be useful in understanding the many evils of modern thought – especially in Germany, which was deeply infected by Kant’s poisonous and foolish ideas.
 Immanuel Kant, An Answer to the Question: What is Enlightenment? (London 2009), pp. 111, 26, and 76 respectively. Future quotes will not be footnoted but will give the page number in the body of text.
 For a quote as well as more information see “Kant and racism,” Philosophical Misadventures: The Thin Ice of Reason; http://www.philosophicalmisadventures.com/?p=20
accessed Sept. 2010. Collections of sayings about the Jews were published so anti-Semites could get ideas from various thinkers without having to bother with a lot of tedious and extraneous philosophical ideas.
 A useful analysis of some problems with Kant’s thought as well as of his relevance to current philosophical trends is found in Stephen R.C. Hicks’ Explaining Postmodernism: Scepticism and Socialism from Rousseau to Foucault (Phoenix AZ, 2004).