Pragmatism is shown in field (7)
I believe the answer is:
realism
'pragmatism' is the definition.
(I know that pragmatism can be written as realism)
'is shown in field' is the wordplay.
'shown in' is an insertion indicator.
'field' becomes 'realm' (synonyms).
'is' put into 'realm' is 'REALISM'.
(Other definitions for realism that I've seen before include "Actuality" , "Representation in an accurate and true to life way" , "Pragmatism" , "Practicality of mailers" , "Literal style in art" .)