Your brother makes an excellent point, which is something I’ve always found amusing about atheists: despite their professed godlessness, their values have an uncanny resemblance to those of their Judeo-Christian heritage.

Not many atheists and secularists are willing to turn the other cheek when someone hits them, not look lustfully at the opposite sex, give everything to the poor and care not for the future. Neither are many Christians.

As an example, I have no trouble imagining a scientific civilization that is brutally unegalitarian, aggressive, atheistic, polygamous, Eugenicist, Darwinian, etc. in its values; in fact this would be my preference.

Look at The Domination. This would fit your vision better than the Sith.