This paper tries to show how can Kant’s understanding of self-determination be incorporated into the modern discours about why and how a human being acts. Kant supports the thought about the existence of free will, but a lot of scientists think that human actions are determined. The main strain that pleads that we are determined by our genes is genetic determinism. This interpretation can lead to a state where actions are justified based on biological predispositions because in that case we can’t be held responsible for them. This kind of understanding of the genetic determinism emerged from the assumption that genetic determinism and free will can’t be reconciled. It was shown that genetic determinism is right when it stresses that in some cases genes can have an impact on the human being, but only in creating biological predispositions. Kant doesn’t abnegate the fact that the human being is a part of the sensorial world and as such lies under the natural laws like the laws of evolution. Nontheless humans are reasonable beings, too. Will is given in reason and the moral law is a factum of reason Kant concludes that free will consists in pursuing our own law. Because of that do moral actions fall under the field of freedom and can’t be determined by biological predispositions.