Freud in effect readopted the original definition in "Beyond the Pleasure Principle", this time applying it to a different principle. He asserted that on certain occasions the mind acts as though it could eliminate tension entirely, or in effect to reduce itself to a state of extinction; his key evidence for this was the existence of the compulsion to repeat. Examples of such repetition included the dream life of traumatic neurotics and children's play. In the phenomenon of repetition, Freud saw a psychic trend to work over earlier impressions, to master them and derive pleasure from them, a trend was prior to the pleasure principle but not opposed to it. In addition to that trend, there was also a principle at work that was opposed to, and thus "beyond" the pleasure principle. If repetition is a necessary element in the binding of energy or adaptation, when carried to inordinate lengths it becomes a means of abandoning adaptations and reinstating earlier or less evolved psychic positions. By combining this idea with the hypothesis that all repetition is a form of discharge, Freud reached the conclusion that the compulsion to repeat is an effort to restore a state that is both historically primitive and marked by the total draining of energy: death. Such an explanation has been defined by some scholars as "metaphysical biology".