 To be sure, at an ultimate level, the only actions of substances are changes of perceptions. Thus, at the ultimate level, the appetitions are not so much the tendencies impelling a person towards voluntary motions of the human body (although at the level of well-founded phenomena this may indeed be the case) but rather tendencies arising out of present perceptions (present appearances) towards new perceptions. This explains why Leibniz defines appetitions in the initially surprising way noted above, as “tendencies from one perception to another”—another perception, that is.