Kants Kritik der praktischen Vernunft (1788) steht zu Unrecht oft im Schatten der Kritik der reinen Vernunft und der Grundlegung zur Metaphysik der Sitten. Tatsächlich sind die Grundelemente der Kantischen Moralphilosophie im Gegensatz zu vielen Thesen der ersten Kritik bis heute weitgehend anerkannt, und erst der Nachweis der zweiten Kritik, dass Freiheit wirklich ist, macht "den Schlussstein von dem ganzen Gebäude eines Systems der reinen, selbst der spekulativen Vernunft aus". Entlang der Stichworte reiner Wille, gesetzgebende Form der Maxime, transzendentale Freiheit, (...) Autonomie und Faktum der Vernunft zeigt Kant in der "Analytik", dass reine Vernunft "für sich" praktisch sein, nämlich den Willen bestimmen kann. Die "Dialektik" sichert den Ideen von der Existenz Gottes und der Unsterblichkeit der Seele objektive Realität und untersucht das Verhältnis von theoretischer und praktischer Vernunft. Die "Methodenlehre" schließlich skizziert eine Theorie moralischer Erziehung, die für den heutigen Ethikunterricht noch aktuell ist. Die zwölf Beiträge dieses kooperativen Kommentars, der anlässlich des 300. Jubiläums Immanuel Kants in einer 3., überarbeiteten Auflage erscheint, rekonstruieren die Argumente eines Schlüsseltextes der Moralphilosophie und prüfen die sachliche Überzeugungskraft. Mit Beiträgen von: Karl Ameriks, Reinhard Brandt, Eckart Förster, Otfried Höffe Allen W. Wood Christoph Horn, G. Felicitas Munzel, Onora O'Neill Annemarie Pieper, Friedo Ricken, Nico Scarano. (shrink)

Discussing the concept of duty in Groundwork 1, Kant refers to a ‘second proposition’ and a ‘third proposition’, the latter being a ‘Folgerung aus beiden vorigen’. However, Kant does not identify what the ‘first proposition’ is. In this paper, I will argue that the first proposition is this: An action from duty is an action from respect for the moral law. I defend this claim against a critique put forward by Allison according to which ‘respect’ is a concept that is (...) not, and could not be, introduced in paragraphs 9–13 of Groundwork 1. Further, I will argue that the first proposition as I understand it can also be reconstructed as the conclusion (‘Folgerung’) of a deductive argument proper; however, I will also discuss the option that ‘Folgerung’ could be understood as a corollary rather than a conclusion. Finally, Allison's own interpretation will be criticized. (shrink)

Immanuel Kant (1724–1804) argued that moral requirements are based on a standard of rationality he dubbed the “Categorical Imperative” (CI). Immorality thus involves a violation of the CI and is thereby irrational. Other philosophers, such as Locke and Hobbes, had also argued that moral requirements are based on standards of rationality. However, these standards were either desirebased instrumental principles of rationality or based on sui generis rational intuitions. Kant agreed with many of his predecessors that an analysis of practical reason (...) will reveal only the requirement that rational agents must conform to instrumental principles. Yet he argued that conformity to the CI (a non-instrumental principle) and hence to moral requirements themselves, can nevertheless be shown to be essential to rational agency. This argument was based on his striking doctrine that a rational will must be regarded as autonomous, or free in the sense of being the author of the law that binds it. The fundamental principle of morality — the CI — is none other than the law of an autonomous will. Thus, at the heart of Kant's moral philosophy is a conception of reason whose reach in practical affairs goes well beyond that of a Humean ‘slave’ to the passions. Moreover, it is the presence of this self-governing reason in each person that Kant thought offered decisive grounds for viewing each as possessed of equal worth and deserving of equal respect. (shrink)