Complex sentence: Trying to win the debate on a meta level is an exercise in futility, not only because you are combating personal experiences, scientific knowledge, and cultural expectations, but also because it is an argument that properly belongs in.
Split into simpler sentences: Trying to win the debate on a meta level is an exercise in futility. It is an exercise in futility, not only because you are combating personal experiences, scientific knowledge, and cultural expectations, but also because it is an argument that properly belongs in.