Belief which can come from the Right or the Left? (5)

I believe the answer is:

tenet

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'belief' is the definition.
(synonyms)

I can't explain the remainder of the clue.

(Other definitions for tenet that I've seen before include "Article of belief" , "Palindromic principle or belief" , "Belief or doctrine - a palindrome" , "Doctrine; principle held" , "Conviction" .)

I've seen this clue in The Times.

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