Be wary of scientific dualisms.
Approach them with caution, the way demolition experts regard bombs, likely to explode, in this case into unproductive argument and the obscuring of truth. "Opposing forces" are the scientific version of the original dualism—good vs evil and darkness vs. light. Instead, of acting in opposition, in nature two forces are likely to dependent, interactive and interwoven; sometimes they are merely two names for the same thing.
For example:
Brain vs Mind
Mind vs Body
Emotion vs Reason
Nature vs Nurture
Us vs Them
Seek unity.
Remember always that it is easy to be in possession of some facts, extraordinarily difficult to know the truth.