The image of cycles in which the universe returns to re-enact exactly the same course of events is common to many religions, and was a theme of much Greek thought, including that of the Stoics. Usually recurrence is thought of in terms of events that cycle in a common-sense, linear time, but the possibility of time itself cycling was also considered. The contradiction that in that case the ‘later’ events would be numerically identical with the earlier, so that everything happens only once after all, was noticed by Eudemus of Rhodes, a pupil of Aristotle. A doctrine of recurrence was held by Plotinus and Origen. The notion of endless recurrence was embraced by Nietzsche in 1882, and is explored in the notebooks making up The Will to Power. It is not clear whether for Nietzsche the cycle is scientifically probable, but it provides a litmus test for success in life: if we succeed in giving the right style to our actions we can joyously affirm their return, but otherwise we cannot.