Kant divides philosophy into logic, physics and ethics. Logic is today a mathematical science, and either incorprates or is incorporated by math. Physics and ethics are the empirical sciences, distinguished from logic which can never be dependent on the empirically given, since it's task is to describe the laws of reason. Physics extrapolates the laws of nature from the manifold flux of real events and processes which dictate to it the content it has to address. Ethics is eqally empirical, dealing with what ought to occur and, in Kant's opinion, therefore dealing with freedom.
While contemporary theory and philosophy have a problem with the idea of freedom, the term serves as well as any other to distinguish the activities of the human sciences, that swathe of academic disciplines that amalgamates the arts, humanities and social sciences. When we deal with human activity, if Kant is right, we deal with ethical issues. All rational creatures, he says, must abide by such simple, logically compelling rules as 'Thou shalt not lie'. And yet, at every turn, the world lies – for the Platonist and the Marxist, the Nietzshean and the postcolonial scholar alike. Not only does nature lie through camouflage and stealth; society embraces it. To the extent that society affords its citizens freedom, it lies when it gives them rules. To the extent that it does not, it lies when it pormises to. Kant's truth is founded in dissimulation.