Temporal existence is often contrasted with spiritual existence, which many religions teach is eternal. The American system of government features a separation of church and state—that is, a separation of spiritual and temporal authority. But such separation is relatively recent. In past centuries, the Roman Catholic Church exerted temporal authority—that is, political power—throughout much of Europe, and the Church of England has always been officially headed by the temporal ruler of Great Britain. Temporal isn't always used in religious contexts; for example, child psychologists often measure "temporal processing"—that is, speed of thinking—in children with mental difficulties. Note that temporal may also mean "near the temples (of the head);" thus, your brain's temporal lobes are situated at your temples. But this temporal is based on a different Latin root.