It's logical that man followed firm to Split (8)
I believe the answer is:
coherent
'it's logical' is the definition.
(similar in meaning)
'man followed firm to split' is the wordplay.
I cannot really understand how this works, but
'man' could be 'he' (he refers to a man) and 'he' is located in the answer.
'firm' could be 'co' (a firm is a company) and 'co' is present in the answer.
'split' could be 'rent' (past tense of 'rend' meaning to split) and 'rent' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'that' is the link.
Can you help me to learn more?
(Other definitions for coherent that I've seen before include "Clear and logical, not confused" , "Rational" , "making sense" , "Logical and lucid" , "Sticking together" .)