ABSTRACT
Smith maintains that services, however useful, are unproductive because they are not durable and so not accumulable, and moreover because they exchange labour for revenue, not for capital. The authors also claim that intellectual labour and services are useful for the production process. Labour is productive only when it produces more than the producer's consumption, that is when it yields rent, interest or profit. Labour is neither directly nor indirectly productive it simply subtracts wealth from others. Dutens defended the productive nature of professionals and of intellectual labourers with contradictory arguments. He considered the activities regarding the law, taxes and defence unproductive, since they only protect the given order. Less convincingly, many authors–while supporting the productive nature of intellectual labour–use concepts like "spiritual goods", "moral capital", "inner goods". In some authors, the idea of moral goods leads to an attitude of vaguely spiritual and holistic attitude, hostile to the idea of the division of labour.
