As Sidgwick sees it, one of the central issues of ethics is whether these three methods can be harmonized with each other. Sidgwick argues that this is possible for "intuitionism" and "utilitarianism". But a full success of this project is impossible since egoism, which he considers as equally rational, cannot be reconciled with utilitarianism unless "religious assumptions" are introduced. Such assumptions, for example, the existence of a personal God who rewards and punishes the agent in the afterlife, could reconcile egoism and utilitarianism. But without them, we have to admit a "dualism of practical reason" that constitutes a "fundamental contradiction" in our moral consciousness.