Sort of path taken by the serious student (6)
I believe the answer is:
gravel
'sort of path' is the definition.
The answer and definition can be both related to thinking as well as being verbs in their base form.
Perhaps you can see a link between them that I don't see?
'the serious student' is the wordplay.
'the serious' becomes 'grave' (I've seen this before).
'student' becomes 'l' (as in L-plates for learner drivers).
'grave'+'l'='GRAVEL'
'taken by' acts as a link.
Can you help me to learn more?
(Other definitions for gravel that I've seen before include "Coarse sand mixed with small stones" , "Mass of small stones" , "Loose fragments of rock" , "Rocky fragments" , "Rock fragments and pebbles" .)