0 the process of making judgments about something based on sensible thinking or logic (= a formal scientific method of thinking about ideas):
Aquinas takes a rather dim view of discursive reason or ratiocination as compared to sheer understanding.
The detective in the story is known for his gifts of observation and ratiocination.
Ratiocination is methodical and logical reasoning.
It is knowledge that is assumed to arise from the process of ratiocination alone.
