The basic cause of totalitarianism is two ideas: men’s rejection of reason in favor of faith, and of self-interest in favor of self-sacrifice. If this is a society’s philosophical consensus, it will not be long before an all-powerful Leader rises up to direct the faith and sacrifice that everyone has been extolling. His subjects cannot resist his takeover, neither by exercising their faculty of thought nor their passion for values, because these are the two priceless possessions they have given up. The end result is thought control, starvation, and mass slaughter.
–Ayn Rand, Introduction to We the Living
This is about as succinct a statement of this concept as I’ve seen.