John Locke believed that a human baby started out as a tabula rasa, or a blank tablet, when it was born and gradually attained knowledge by a process of accumulating experience. Although babies have no knowledge, they do have a limited group of innate ideas , such as causation, that condition their understandings of their perceptions. By accumulating perceptions, storing them in memory, and comparing them, humans gradually learn how to interpret individual perceptions and sequences of perceptions in a way that makes them meaningful, i.e. figuring out that a certain pattern of colours and sounds can be understood as a human being or that if an object is dropped it will fall. Thus perception leads to knowledge but learning makes sense of perceptions.