the article analyses and confronts the concepts of reason and freedom in kant and hegel in a contemporary perspective. it refutes the current interpretations of these authors and makes relevant the priority of freedom. reason is possible only because of the existence of freedom. such the famous circle acknowledged by kant: reason is the (logical) grounding of freedom, whilst the latter is the (ontological, effective) grounding of reason. hegel will agree with that "circle of feedback", but will endeavour to develop dialectically what in the analytical kant appears as a set of juxtaposed issues. in the swabian philosopher, both issues are incardinated in a much wider and integrated movement.