The Philosophy of Kant - The Moralist and the Critic

Kant's critique of human freedom involves rejecting its definition as the ability to choose between alternatives; he compares this notion of freedom with that of a turnspit, projectile in flight or movement of clock hands.

He holds that free action must have irreducibly mental causes and must be motivated by moral considerations rather than natural desires.

The Critique of Pure Reason

Kant's Critique of Pure Reason outlines his mature metaphysics and epistemology, offering his most compelling arguments against empiricists and dogmatists, and serving as a cornerstone of modern philosophy.

Kant's central thesis was that we must distinguish the empirical world of appearances from the real, independent world of things in themselves. This distinction formed the basis of his doctrine of transcendental idealism - an innovative shift in space-time metaphysics.

He further contends that God is an artificial being; an abstract concept, formed through reason's understanding of cause-and-effect relationships; no analysis can produce its predicate; similarly there exist synthetic a priori truths (such as 7+5 = 12) which must exist but which cannot be proven through observation alone.

Kant uses these arguments to demonstrate a critical flaw in Hume's skeptical skepticism of knowledge pertaining to necessity. He maintains that natural law and moral law of human actions exist independently from each other. According to Kant's view, natural law will lead to the ultimate end goal being a perfect state for humanity with political institutions founded upon rationality as the result. However, this is not predicted in advance but an inevitable result resulting from nature being subject to transcendental laws of cause-and-effect established a priori by categories governing it all.

The Critique of Judgment

Kant, in his Critique of Judgment, attempted to present an inclusive defense of transcendental idealism than in any of his previous critiques. He contended that human perception of the empirical world is not simply an accumulation of appearances but instead is composed of transcendental concepts derived from space/time/matter/cause and therefore pervading all aspects of experience.

Kant's first part of his Critique addresses aesthetic judgments. According to Kant, there are four possible reflective judgments of aesthetic objects: agreeable, beautiful, sublime and good. These come from the Table of Judgements from Pure Reason but differ from it because they can only be subjectively assessed according to individual inclination rather than pleasing others. He claims that agreeable and good qualities exist naturally while beautiful and sublime qualities result from experiencing aesthetic objects with the idea of creating perfect wholes.

Kant's argument for the categorical nature of goodness is a complex and controversial one. He asserts that all moral theories should begin from what he calls "the unconditional good," whether this be something conditionally good (which would require preference) or inherently good - like Kant claims it should.

The Critique of Teleological Judgment

Kant argues in his second antinomy that any theory of natural ends must be grounded in a concept of purposes. Kant associates this notion of purposes with human culture, suggesting that humans possess the capacity to self-assemble such systems of "purposes" as they reconfigure nature according to their individual desires.

Kant's philosophy can best be understood when taken as a whole: morality and natural science were on an equal rational footing according to him.

Problematic with teleological judgment is that it assumes causal relationships in nature are mechanical. This then leads to the idea that physical ends can be found among things whose parts serve both means and ends for one another (Kant uses the Greek term telos for "end" or "purpose").

Hume's skeptical views about knowledge of necessity were breached by Kant's notion of purpose; thus creating an insurmountable obstacle to empirical science and morality. Kant recognized that causal determinism alone wasn't enough of an issue here - Judgment needed to play its part as well, having to overlap both with Understanding and Reason in some way or another. He proposed creating a third way by developing non-mechanical causality principles which can act as mediators between Understanding's deterministic framework and Reason's free will.

The Critique of Practical Reason

Contrary to its other sections, Kant's Critique of Practical Reason does not resolve its own antinomies or present its own metaphysics (though Kleingeld 1994 and Guyer 2000a do discuss its implications for metaphysics). Instead, Kant provides an argument which is theoretical yet practical in application: an argument regarding principles pure practical reason must set for itself.

Kant's moral theory begins with an account of what is unconditionally good, with all forms of goodness eventually traceable back to a single, unconditional law: the Categorical Imperative. Kant further asserts that three postulates attached to this law: immortality, freedom considered positively and God.

All principles derived from reason are meant to have their source in its laws themselves, rather than personal inclinations or religious doctrine. Kant recognized this fact when he stated that any principle dependent on an external source such as reason's laws or religious dogma could never provide legitimate substantive guidance as it relies on motivations or situations other than its own. Therefore he labeled any reasoning which seeks significant guidance outside itself heteronomous (directed by another authority other than oneself); similar to instrumental reasoning which decides on means by which predefined ends are achieved.