Speculates or introspects at first in academic papers (9)
I believe the answer is:
'speculates' is the definition.
(I know this)
'or introspects at first in academic papers' is the wordplay.
'at first' suggests taking the first letters.
'in' is an insertion indicator.
'academic papers' becomes 'theses' (plural of thesis).
The initial letter of 'introspects' is 'i'.
'ori' put into 'theses' is 'THEORISES'.
(Another definition for theorises that I've seen is " Speculates".)