 However, Lewis thought that judgements about how a valued experience contributes to the value of a life as a whole, unlike some terminating judgements about how one valued experience will yield another valued experience, are not decisively verifiable or falsifiable. First, any attempt to apprehend a life as a whole and the value of it as experienced goes beyond the specious present of experience and relies on memory and expectation of past and future experience and their values, and thereby leaves room for error. Second, any attempt to simplify the problem by breaking a whole life into parts and apprehending their value, and then calculating the probability of their contributing to a good life as a whole, also leaves room for error.