 Squire’s taxonomy has been extremely influential, but alternative taxonomies have been proposed in both psychology and philosophy. In psychology, Atkinson and Shiffrin (1968) proposed a multi-store model in which kinds of memory are distinguished in terms of their temporal duration. Ultra short term memory refers to the persistence of modality-specific sensory information for periods of less than one second. Short term memory refers to the persistence of information for up to thirty seconds; short term memory, which receives information from ultra short term memory, is to some extent under conscious control but is characterized by a limited capacity. Long term memory refers to the storage of information over indefinitely long periods of time; long term memory receives information from short term memory and is characterized by an effectively unlimited capacity. Though this taxonomy does not distinguish among importantly different kinds of long term memory—in particular, it does not distinguish between episodic and semantic memory—it has been applied productively in psychological research. With rare exceptions (Werning &amp; Cheng 2017), however, it has not informed philosophical discussions.