Full Idea
The legislation of human reason (philosophy) has two objects, nature and freedom, and thus contains the natural law as well as the moral law, initially in two separate systems, but ultimately in a single philosophical system.
Gist of Idea
Reason has two separate objects, morality and freedom, and nature, which ultimately unite
Source
Immanuel Kant (Critique of Pure Reason [1781], B868/A840)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.695
A Reaction
Pure reason is for nature, and practical reason (which has priority) is for freedom and morality. There is a streak of religiosity in Kant which makes him give morality and normativity priority over truth and science.
Related Idea
Idea 21455 We only understand what exists, and can find no sign of what ought to be in nature [Kant]