By capital we understand everything that, from the special use by the individual, or from its being placed at the disposal of others, produces a reve… - Albrecht Daniel Thaer

The word " economy" has latterly been used in various senses; the Germans give it a very indefinite signification.
Judging from its etymology and original signification, the Greeks seem to have understood by it the establishment and direction of the menage, or domestic arrangements.
Xenophon, in his work on economy, treats of domestic management, the reciprocal duties of the members of a family and of those who compose the household; and only incidentally mentions agriculture as having relation to domestic affairs. This word is never applied to agriculture by Xenophon, nor, indeed, by any Greek author; they distinguish it by the terms, georgic geoponic.
The Romans give a very extensive and indefinite signification to the word "economy." They understand by it, the best method of attaining the aim and end of some particular thing; or the disposition, plan, and division of some particular work. Thus, Cicero speaks of oeconomia causae, oeconomia orationis; and by this he means the direction of a law process, the arrangement of an harangue. Several German authors use it in this sense when they speak of the oekonomie eines schauspiels, or eines gedichtes, the economy of a play or poem. Authors of other nations have adopted all the significations which the Romans have attached to this word, and understand by it the relation of the various parts of any particular thing to each other and to the whole—that which we are accustomed to term the organization. The word "economy" only acquires a real sense when applied to some particular subject: thus, we hear of "the economy of nature," "the animal economy," and " the economy of the state" spoken of. It is also applied to some particular branch of science or industry; but, in the latter case, the nature of the economy ought to be pointed out, if it is not indicated by the nature of the subject.

The physicians in Celle were fifteen years behind in their practice; they had heard of a new style of practice, but regarded it as a mere chimera. When I ventured to say a word or two, they did not understand me: when I appealed to some great authority, they were ignorant of it: when I spoke from my own practical experience, they looked at me, from head to foot, and said sneeringly, "Well, well; experience will come in time." But when by chance I ventured to make some proposal, they turned round, and wondered where they should find room enough in the churchyards to bury my patients. The great applause with which my Dissertations had been received in all the learned journals, even in England as well as in France, gave me courage, hoping that this circumstance would make some impression on the mind of the public; but it was generally thought I had ill employed my time, and knew little or nothing. Being obliged to frequent society, I was so disgusted with the general tone and the topics of their conversation, that I was almost in despair; at last, some young ladies treated me with more attention.

The science of agriculture does not lay down any positive rules, but it develops the motives by which the best possible method of proceeding may be discovered and successfully pursued. In fact, the art executes some law given and received, but it is from science that law emanates.