But in the sciences of morals and politics, men are found far less tractable. To a certain degree, it is right and useful that this should be the case. Caution and investigation are a necessary armor against error and imposition. But this untractableness may be carried too far, and may degenerate into obstinacy, perverseness, or disingenuity. Though it cannot be pretended that the principles of moral and political knowledge have, in general, the same degree of certainty with those of the mathematics, yet they have much better claims in this respect than, to judge from the conduct of men in particular situations, we should be disposed to allow them. The obscurity is much oftener in the passions and prejudices of the reasoner than in the subject. Men, upon too many occasions, do not give their own understandings fair play; but, yielding to some untoward bias, they entangle themselves in words and confound themselves in subtleties. How else could it happen (if we admit the objectors to be sincere in their opposition), that positions so clear as those which manifest the necessity of a general power of taxation in the government of the Union, should have to encounter any adversaries among men of discernment? Though these positions have been elsewhere fully stated, they will perhaps not be improperly recapitulated in this place, as introductory to an examination of what may have been offered by way of objection to them. They are in substance as follows: A government ought to contain in itself every power requisite to the full accomplishment of the objects committed to its care, and to the complete execution of the trusts for which it is responsible, free from every other control but a regard to the public good and to the sense of the people. As the duties of superintending the national defense and of securing the public peace against foreign or domestic violence involve a provision for casualties and dangers to which no possible limits can be assigned, the power of making that provision ought to know no other bounds than the exigencies of the nation and the resources of the community. As revenue is the essential engine by which the means of answering the national exigencies must be procured, the power of procuring that article in its full extent must necessarily be comprehended in that of providing for those exigencies. As theory and practice conspire to prove that the power of procuring revenue is unavailing when exercised over the States in their collective capacities, the federal government must of necessity be invested with an unqualified power of taxation in the ordinary modes.