Full Idea
The concept is always possible if it does not contradict itself (the logical mark of possibility). Yet it can be an empty concept. ...We cannot infer from the possibility of the concept (logical possibility) to the possibility of the thing (real).
Gist of Idea
A concept is logically possible if non-contradictory (but may not be actually possible)
Source
Immanuel Kant (Critique of Pure Reason [1781], B624/A596 n)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.566
Related Idea
Idea 18796 Formal experience conditions show what is possible, and general conditions what is necessary [Kant]