The early Schlick developed an evolutionary biological account of play. He contrasted play with work. Where work encompasses all activity that is undertaken for the sake of some practical outcome, play renders what was previously a mere means into an end enjoyable in itself. Schlick thus distinguished between aesthetic, religious, scientific, and ethical game types. This paper shows that this typology underlies his later attempts to naturalize these fields, and allows us to clarify the relation between object-games and their description (...) within the scientific game. Schlick's demarcation between aesthetic and scientific games arguably prefigures the Vienna Circle's anti-metaphysical stance. (shrink)