Kant argued that humans are obliged to bring about the summum bonum: the two central aims of moral virtue and happiness, where happiness arises out of virtue.

As ought implies can, Kant argued, it must be possible for the summum bonum to be achieved.

The same is true for Thomas Aquinas, Christian Wolff and Immanuel Kant, who claim that there are duties to ourselves as Aristotle did, although it has been argued that, for Aristotle, the duty to one's self is primary.

Second, Kant argued that it was not the consequences of actions that make them right or wrong but the motives of the person who carries out the action.

Kant also argued that existence is not a " real " predicate, but gave no explanation of how this is possible.

Friedrich Nietzsche argued that Kant confuses tautology and petitio principii, and ridicules his pride in tackling " the most difficult thing that could ever be undertaken on behalf of metaphysics .".

Kant argued for the establishment of a peaceful world community, not in a sense of a global government, but in the hope that each state would declare itself a free state that respects its citizens and welcomes foreign visitors as fellow rational beings, thus promoting peaceful society worldwide.

Kant argued against all three forms of materialism, subjective idealism ( which he contrasts with his " transcendental idealism ") and dualism.

In Prussia, the development of spiritual renewal as a means to engage in the struggle against Napoleon was argued by, among others, Johann Gottlieb Fichte ( 1762-1814 ), a disciple of Kant.

Immanuel Kant argued for sceptical theism.

: Whereas David Hume argued that causes are inferred from non-causal observations, Immanuel Kant claimed that people have innate assumptions about causes.

Whereas Cassirer defended the role of rationality in Kant, Heidegger argued for the priority of the imagination.

Kant argued that the structures of logic which organize, interpret and abstract observations were built into the human mind and were true and valid a priori.

The philosopher Immanuel Kant argued that human beings are not capable of direct, unmediated knowledge of the world.

Although Kant considered these mediating structures universal, his student Johann Gottfried Herder argued that human creativity, evidenced by the great variety in national cultures, revealed that human experience was mediated not only by universal structures, but by particular cultural structures as well.

Franz Boas, originally trained in physics and geography, and heavily influenced by the thought of Kant, Herder, and von Humboldt, argued that one's culture may mediate and thus limit one's perceptions in less obvious ways.

Kant argued that there can be exactly the same relation between two completely different objects.

Immanuel Kant and his followers held that shame is heteronomous ; Bernard Williams and others have argued that shame can be autonomous.

" Kant considered critical conscience to be an internal court in which our thoughts accuse or excuse one another ; he acknowledged that morally mature people do often describe contentment or peace in the soul after following conscience to perform a duty, but argued that for such acts to produce virtue their primary motivation should simply be duty, not expectation of any such bliss.

Kant argued that autonomy is demonstrated by a person who decides on a course of action out of respect for moral duty.

In the 19th century, philosopher Immanuel Kant argued in Metaphysics of Morals, § 49 E., that the only legitimate form of punishment the court can prescribe must be based on retribution and no other principle.

Both Jean-Jacques Rousseau, a critic of civil society, and Immanuel Kant argued that people are peace lovers and that wars are the creation of absolute regimes ( Burchill 2001: 33 ).

Consequently, Kant argued, hypothetical moral systems cannot persuade moral action or be regarded as bases for moral judgments against others, because the imperatives on which they are based rely too heavily on subjective considerations.

Although Kant conceded that there could be no conceivable example of free will, because any example would only show us a will as it appears to us — as a subject of natural laws — he nevertheless argued against determinism.

Kant says that happiness should not be our goal, but he also says we should respect moral agents.

In addition, du Bois-Reymond like Kant observed that Le Sage's theory cannot meet its goal, because it invokes concepts like " elasticity " and " absolute hardness " etc., which ( in his opinion ) can only be explained by means of attractive forces.

This method begins with an analysis of human knowing as divided into three levels — experience, understanding, and judgment — and, by stressing the objectivity of judgment more than Kant had done, develops a Thomistic vision of Being as the goal of the dynamic openness of the human spirit.

He strove to replace the nationalist German ideal of racial community with the goal of an ethnically heterogeneous and inclusive European nation based on a communality of culture, a nation whose geniuses were the " great Europeans " such as abbé de Saint-Pierre, Kant, Napoleon, Giuseppe Mazzini, Victor Hugo, and Friedrich Nietzsche.

Immanuel Kant said that " Of the crooked timber of humanity, no straight thing can ever be made ," and yet this was not an expression of the uselessness of mankind itself.

In a paradoxical way, Kant supported in the same time enlightened despotism as a way of leading humanity towards its autonomy.

While Kant admits that humanity could subsist ( and admits it could possibly perform better ) if this were universal, he states in Grounding:

Kant there claimed that the expansion of hospitality with regard to " use of the right to the earth's surface which belongs to the human race in common " ( see common heritage of humanity ) would " finally bring the human race ever closer to a cosmopolitan constitution ".

Kant himself spoke of the " starry skies above " and the " moral law within ", and although Kant did not deny the regularity of the natural world and the reality of humanity ’ s " moral motions ," his philosophy could not bring these two worlds together.

The ethical end is taken to be the idea of humanity, not in the abstract as formulated by Kant, but in the context of the state and of history.

According to Peter Gay, building on Ernst Cassirer's much earlier study of the intellectual progenitors of Kant, the Enlightenment was the creation of a small group of thinkers, his family of philosophes or ‘ party of humanity ’, whose coherent anti-Christian, ameliorist, and individualistic programme of reform developed from very specific cultural roots.

German nationalism as promoted by Herder and Immanuel Kant was Romantic in nature that were based upon the principles of collective self-determination, territorial unification and cultural identity, and a political and cultural programme to achieve those ends.

The maxim of this action, says Kant, results in a contradiction in conceivability ( and thus contradicts perfect duty ).

Kant argued that any action taken against another person to which he or she could not possibly consent is a violation of perfect duty interpreted through the second formulation.

The philosophers Immanuel Kant, Friedrich Schleiermacher and Albrecht Ritschl believed that the kingdom of God referred to a world of ideal human relations and envisaged a perfect Christian society.

One difference is that whereas the Stoics regard external goods as neutral, as neither good nor bad, Kant ’ s position seems to be that external goods are good, but only so far as they are a condition to achieving happiness.

Kant does not encourage acting in order to attain happiness.

Kant writes, " A man even has an indirect duty to seek happiness.