Is there a word for “making two conflicting elements coexist together in a system”?

Solution 1:

There are several options, depending on the precise connotations you prefer. I might start with reconcile. From Cambridge Dictionary:

verb to adjust the way you think about a fact or situation that is opposed to another fact or situation so that you can accept both:
How do we reconcile the seemingly contradictory notions of cutting taxes and balancing the budget?

This is a particularly apt option if you want to emphasize the fact that the two concepts were (or are generally) at odds with one another, but have figured out a way to live with one another.

You said that accommodate doesn't quite work; I could make it fit your example, in the sense

2. To take into consideration or make adjustments for; allow for: an economic proposal that accommodates the interests of senior citizens.

(From The American Heritage Dictionary, via The FreeDictionary.com)

But accommodate, to me, suggests finding room for both concepts without necessarily an implication of direct conflict between the two. I think this may be why it doesn't quite work for you, and might possibly make reconcile seem too strongly "settled" a term, as well.

If that's correct, then you might want to consider negotiate or mediate, both of which emphasize the ongoing struggle and uneasy co-existence between the two concepts. This is a bit of a specialist use of these words, mostly seen in academic-type texts, as in

In our attempt to address the anxiety this provokes and to reintegrate ourselves to the external world, we develop a symbolic system to negotiate our conflicting drives of creation and destruction toward self and other. (Dina Georgis, The Better Story: Queer Affects from the Middle East, 2013)

or

Institutions mediate conflicting desires, and differing institutions will generate differences in outcomes even under the same preference orderings. (Robert Pahre, Democratic Foreign Policy Making: Problems of Divided Government and International Cooperation, 2006)

Because one can negotiate for oneself but a mediator is, by definition, a third party, I would say that negotiate has a bit more of a connotation of volition on the part of the main actor, whereas mediate has more of an implication of an outside force. In your example, negotiate sounds more like hypocrisy is the individual's or society's own, perhaps semi-conscious, mechanism; whereas mediate feels very slightly more automatic, or passive in the non-grammatical sense.

All of these terms are related to the concept of compromise, and you could also look at its synonyms and related terms for more ideas. You could also rewrite your sentence to use compromise itself, e.g. a mechanism to reach a compromise between the conflicting forces etc.

Solution 2:

Juxtapose:

to put things that are not similar next to each other

http://dictionary.cambridge.org/dictionary/english/juxtapose

Hypocrisy, both as a self deception and a social deception, is a mechanism to juxtapose the conflicting forces of self interests and the social interests demanded from oneself.

Solution 3:

I think a good starting point, since your desired connotation isn't entirely clear, would be to look at synonyms of "Integrate" - or perhaps "integrate" itself works for you.

https://www.thesaurus.com/browse/integrate

Words like "join" and "combine" feel too weak for the point you're probably trying to make, whereas words like "fuse" and "meld" feel too jargon-ish and physical.

I know this thread is old, but I didn't feel like the question was definitively resolved for people who land on this page in the future.