 D1 may be taken as the traditional definition of deception, at least in the case of other-deception (Baron 1988, 444 n. 2). As contrasted with ‘lying,’ ‘deceive’ is an achievement or success verb (Ryle 1949, 130). An act of deceiving is not an act of deceiving unless a particular result is achieved. According to D1, that result is a false belief. Note that D1 is not restricted to the deception of other persons by other persons; it applies to anything that is capable of having beliefs, such as (possibly) chimpanzees, dogs, and infants.