But, to come more closely to the present case, _self-interest_ will be airline tickets but a weak barrier against the sallies of _passion_: particularly where it has been daily indulged in its greatest latitude, and there are no laws to restrain its calamitous effects. This is a fact, almost universally known, and affords us this proof, that having learned with facility such of the mechanical arts, as they have been taught, they are capable of attaining any other, at least, of the same class, if they should receive but the same instruction. But if the contrary of this is true, which reason must immediately evince, it is evident that no custom established among men was ever more impious; since it is contrary to _reason, justice, nature, the principles of law and government, the whole doctrine, in short, of natural religion, and the revealed voice of God_. This fundamental resemblance between two such apparently incommensurable things as the buying of material commodities and the borrowing of capital is highly significant; it is another instance of that order in the economic world, of which the reader may now be growing weary. But assumptions of this kind are legitimate only when there is no reason to suppose that the cause, the effects of which are being studied, will itself produce a change in the "other things. The higher the rate of interest, the higher the return which a man could obtain by buying gilt-edged securities, the lower will be the price that he will pay for a piece of land which yields a given rent. Moreover, business men may not calculate reasonably on the information which they have. These payments _tend_ to equal the payments which the same agents could have commanded in alternative employments. As against David or David's important supporters men like Uriah had no civil rights that could be enforced. Cheap last minute flights from cardiff airport even, he may have taken some of Jefferson's strictures as aimed at himself. Between 1876 and 1890 the investment in railways had far more than doubled, and, during the last five years of this period, the increment had been at an average of about $450,000,000 annually. It could be bought and sold and inherited like an advowson, or right to dispose of a cure of souls in the English Church, or of a commission in the English army.