Full Idea
For Kant, the will is a causality, and the concept of a causality entails laws; a causality which functions randomly is a contradiction.
Gist of Idea
The concept of causality entails laws; random causality is a contradiction
Source
report of Immanuel Kant (Critique of Pure Reason [1781]) by Christine M. Korsgaard - Intro to 'Creating the Kingdom of Ends' Ch.1
Book Reference
Korsgaard,Christine M.: 'Creating the Kingdom of Ends' [CUP 1996], p.25
A Reaction
This seems to be a rather Humean view, which may be confusing the epistemology (of how we might detect causes) from the ontology (of what causation is). Where is the logical contradiction in random unpredictable causes?