In essence, analysts accept argument for school (6)
I believe the answer is:
lyceum
'for school' is the definition.
(lyceum is a kind of school)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for lyceum that I've seen before include "hall" , "School of thought" , "Garden where Aristotle taught philosophy - London theatre" , "Aristotle's teaching place" , "Aristotle's garden" .)