Thinks logically (7)
I believe the answer is:
reasons
'thinks logically' is the definition.
('reason' can be a synonym of 'think logically')
This is the entire clue.
(Other definitions for reasons that I've seen before include "Motives, explanations" , "Justifications or motives" , "Debates; thinks out" , "Period of reduced economic activity" , "excuses" .)