Certain remarks in that work show that Kant had changed his mind about the idea of a critique of practical reason.

[6] The third section titled "Transition from metaphysics of morals to the critique of pure practical reason" was written to accomplish what he originally thought was at least partially needed in a critique of pure practical reason to properly set up a metaphysics of morals.

The Doctrine of Method discusses moral education and how "one can provide the laws of pure practical reason with access to the human mind and influence on its maxims".

The conclusion was that pure theoretical reason must be restrained, because it produces confused arguments when applied outside of its appropriate sphere.

He suggests that many of the defects that reviewers have found in his arguments are in fact only in their brains, which are too lazy to grasp his ethical system as a whole.

As to those who accuse him of writing incomprehensible jargon, he challenges them to find more suitable language for his ideas or to prove that they are really meaningless.

Practical reason is the faculty for determining the will, which operates by applying a general principle of action to one's particular situation.

For Kant, a practical principle can be either a mere maxim if it is based on the agent's desires or a law if it applies universally.

He ends this chapter by discussing Hume's denial of the claim that the concept of causation possesses any objective validity.

It is subjective necessity (habit), according to Hume, that makes us view events that occur repeatedly alongside or after one another as being causally connected.

Thus he would lack the necessary empty conception of unconditioned causation necessary to prevent the conflating of the phenomenal and noumenal worlds.

Kant begins by explaining how, for practical reason, every motive one has intends some effect on the world, whose realization is the production of its object.

In contrast, the concept of an object of pure practical reason is one whose possibility is distinguished from impossibility in virtue of its capacity to be brought about by a willing of the necessary action independently of one's material conditions for doing so.

The only alternative is to mistakenly understand the Good as the pursuit of pleasure and evil as the production of pain to oneself.

In this chapter, Kant makes his clearest and most explicit formulation of the position he adopts with respect to the question of the fundamental nature of morality.

Kant states that the Analytic of the Critique of Pure Reason begins by analyzing the a priori elements of sensibility (space and time), then examines the most fundamental and essential concepts of the human mind with regard to theoretical knowledge (the categories), and lastly ends with principles.

In this case, the antinomy consists in the fact that the object of pure practical reason must be the highest good (Summum bonum).

This postulate allows us to conceive how it is possible for us in some way to achieve a will that is completely adequate to the moral law, viz., a will similar to the holy will.

We therefore need to postulate that there is an omniscient and omnipotent God who can order the world justly and reward us for our virtue.

In the first Critique, the Doctrine of Method plans out the scientific study of the principles of pure theoretical reason.

In his view, even if we could produce a simulacrum of a moral society, it would all be an enormous theater of hypocrisy, since everyone would inwardly, privately continue to pursue his or her own advantage.

Almost any time there is a social gathering of some sort, the conversation will include gossip and argumentation which entails moral judgments and evaluations about the rightness or wrongness of the actions of others.

Even people who normally do not enjoy intricate arguments tend to reason acutely and precisely when they are caught about in the justification or condemnation of the moral worth of the actions of their next-door neighbor or the deceased.

The first of these methods, argues Kant, is destined to fail because students will not come to understand the unconditional nature of duty.

This method also leads students to associate morality with the impossible theatrics of melodrama, and therefore to disdain the everyday obligations they should be fulfilling as beneath them.

[39] Kant ends the second Critique on a hopeful note about the future of ethics, stating that "[t]wo things fill the mind with ever new and increasing admiration and reverence, the more often and more steadily one reflects on them: the starry heavens above me and the moral law within me".

[40][41] The wonders of both the physical and the ethical worlds are not far for us to find: to feel awe, we should only look upward to the stars or inward to the moral law which we carry within us.

The second Critique exercised a decisive influence over the subsequent development of the field of ethics and moral philosophy beginning with Johann Gottlieb Fichte's Doctrine of Science.

Fichte felt that studying Kant's critical philosophy in 1790 helped him overcome his crisis of metaphysical determinism.

Beck asserts that Kant's "second critique" serves to weave each of these divers strands into a unified pattern for a comprehensive theory on moral authority in general.