Arithmetic is mechanical--geometry is reasoning; surely it was more befitting to compare reason with reason, when endeavouring to discover the true way of perfecting reason. Geometry is, of all sciences, reputed the most conclusive in its arguments--and we know it is distinguished above all sciences for carefulness in its data. It begins with axioms, the most indubitable of all data, and its subsequent conclusions are founded only on established facts--and to be sure that they are established facts, the geometer, before he employs them, establishes them himself. If an analogy is to decide the province of logic, here is an analogy whose pretensions over those of arithmetic are eminent. So conclusive did Dr. Whately deem the argument just examined, that he many times, in various forms, reproduced it. One of the last instances is under the head of 'Fallacies.' 'It has been made a subject of bitter complaint against logic, that it presupposes the most difficult point to be already accomplished; viz., the sense of the terms to be ascertained. A similar objection might be urged against every other art in existence e.g., against agriculture, that all the precepts for the cultivation of land presuppose the possession of a farm.'* * Logic, chap. 3. Fallacies, sec. 2. Already has been pointed out what may reasonably induce a suspicion of the soundness of these analogies; viz., that their author found it necessary to disregard them and introduce, from other branches of knowledge, certain disquisitions on the 'sense of terms.' With regard to this particular instance, it may be observed, that though treatises on agriculture do presuppose the possession of a farm, they do not presuppose the knowledge requisite for cultivating it, but inform _fully_ of soil, and seed, and crops. So logic may be allowed to presuppose the existence of the universe, whence truth is drawn, or the existence of language, 'whereby it is expressed; but it is surely not to _pre-suppose_ the knowledge of facts and terms, the great instruments for the cultivation of truth. Agricultural treatises hardly warrant this inference. There are the representations that induced the confession that 'Logic is not so much an instrument of acquirement as of defence. It is a good armour to buckle on when compelled to battle for our heritage, but a poor implement for its cultivation.'* All _practical_ arts include a knowledge of materials as well as implements. Platers, ignorant of the nature of metals, cabinetmakers, of the different species of wood, make but sorry artizans; and in like manner, reasoners, unacquainted, at least in a general way, with the accuracy of what is reasoned about, make but sorry logicians.**