The fact is, that labour once spent has no influence on the future value of any article: it is gone and lost for ever. In commerce, by-gones are for ever bygones; and we are always starting clear at each moment, judging the values of things with a view to future utility. Industry is essentially prospective, not retrospective; and seldom does the result of any undertaking exactly coincide with the first intention of its founders (ibid.: 59).