Government is not made in virtue of natural rights, which may and do exist in total independence of it, and exist in much greater clearness, and in a much greater degree of abstract perfection but their abstract perfection is their practical defect.By having a right to everything, men want everything.Government is a contrivance of human wisdom to provide for human wants.Men have a right that these wants should be provided for by this wisdom.Among these wants is to be reckoned the want, out of civil society, of a sufficient restraint upon their passions.Society requires not only that the passions of individuals should be subjected, but that even in the mass and body, as well as in the individuals, the inclinations of men should frequently be thwarted, their will controlled, and their passions brought into subjection.This can only be done by a power out of themselves; and not, in the exercise of its function, subject to that will and those passions which is its office to bridle and subdue.In this sense, the restraints on men, as well as their liberties, are to be reckoned among their rights.But because the liberties and the restrictions vary with times and circumstances, and admit to infinite modifications, they cannot be settled upon by any abstract rule; and nothing is so foolish as to discuss them upon that principle.

　　The moment you abate anything from the full rights of men, each to govern himself, and suffer any artificial, positive limitation upon those rights, from that moment the whole organization of government becomes a consideration of convenience.This is which makes the constitution of a state, and the due distribution of its powers, a matter of the most delicate and complicated skill.It requires a deep knowledge of human nature and human necessities, and of the things that facilitate or obstruct the various ends, which are to be pursued by the mechanism of civil institutions.The state is to have recruits to its strength, and remedies to its distempers.What is the use of discussing a man’s abstract right to food and medicine? The question is upon the method of procuring and administering them.In that deliberation, I shall always advise to call in the aid of the farmer and the physician, rather than the professor of metaphysics.
Why the author prefers the aid of the farmer and the physician rather than the professor of metaphysics?

A.the abstract rights to those of food and medicine are more important

B.the abstract rights are hard to procure and administer

C.the abstract rights are to be pursued by the mechanism of civil institutions

D.because they are regarded as the real consideration of convenience