I’m trying to write the following sentence:
This understanding comes as a contrast with a, then, dominant belief system…
Can I use the adverb ‘then’ between the article and its noun as in the case above?
Answer
Yes, without the commas (unless it is apparent, see edit 2 below).
As pointed out in the comments, you are using "then" as an adverb as in definition 1 of Marriam-Webster
then (adverb)
1 : at that time
2a : soon after that : next in order of time
walked to the door, then turned
b : following next after in order of position, narration, or enumeration : being next in a series
first came the clowns, and then came the elephants
c : in addition : besides
then there is the interest to be paid
3a : as a necessary consequence
if the angles are equal, then the complements are equal
b(1) : in that case
take it, then, if you want it so much
(2) —used after but to qualify or offset a preceding statement
she lost the race, but then she never really expected to win
c : according to that : as may be inferred
your mind is made up, then
d : as it appears : by way of summing up
the cause of the accident, then, is established
but it may also be used as an adjective
then (adjective)
: existing or acting at or belonging to the time mentioned
Edit 2:
You could leave the commas there in the following case (from grammarbook.com)
Rule 5. Use commas to set off nonessential words, clauses, and phrases
as pointed out in the comments, but I would take them out in this case since the meaning of the sentence would be different without the ‘then’.
Attribution
Source : Link , Question Author : Sophia , Answer Author : A Lambent Eye