It would, however, be an error to suppose, that the creation of certain utilities for the producer himself, or for others, constitutes the only end of economic production. The more perfect economic production becomes, the greater grows the pleasure the producer feels in his products, which pleasure is at once the effect and the cause of his success. Hence, production is to a great extent its own end. That this is so in the case of artists is well known. “If you want only progeny from her, a mortal can beget them as well. Let him who rejoices in the goddess, not seek in her the woman,” says Schiller. There is not a really clever workman but has something artistic in his mode of production. And even the meanest productive activity, provided it is neither over-driven nor misdirected, must of itself exert a good influence on the physical and moral development or preservation of the producer. An idle brain is the devil’s workshop.(188) Section XXXI. The Factors Of Production.—External Nature.(189) The division of natural forces which formerly obtained, into organic, chemical and mechanical, is of no great importance in Political Economy. The tendency is more and more to resolve organic forces partly into chemical and partly into mechanical. Between mechanical and chemical forces, again, the boundary is not fixed, heat being always capable of producing motion, and motion always of producing heat. Hence, it is all the more important for us to find a division of the economic gifts (matter, forces(190) and relations) of external nature, into such as are capable of acquiring exchange value, and such as are not. (See § 5.) A. Those gifts of nature which, because they cannot be appropriated by any one, or which at least are inexhaustible as compared with the wants of man, and therefore never have a direct value in exchange, belong either to the class of _free_ goods, in the fullest sense of the word, as, for instance, sunlight and the atmosphere (_supra_, § 5);(191) or they constitute, by reason of their peculiar and intransmissible connection with the whole country, an essential element of the national resources. Section XXXII. External Nature.—The Sea.—Climate. To the last category belongs, for instance, the sea, the only natural boundary of a country, which from a military point of view, constitutes a protection to it, without, at the same time, disturbing peaceful traffic. (_Riedel._) Here, also belong ocean currents, especially when uniformly supported by regular winds,(192) the ebb and flow of the tides, which constitute a piece of commercial machinery of the very greatest importance, particularly when they affect the waters of rivers to a great distance.(193) In this age, when the love of travel is so great and so universal, what prices are paid in many places by strangers for the beauty of a landscape, to its owner.