In reply to No. 1, I ask whether, in the nature of the mind, illustration and explanation must not of necessity proceed from the lower to the higher? or whether a boy is to be taught his addition, subtraction, multiplication, and division, by the highest branches of algebraic analysis? Is there any better way of systematic teaching, than that of illustrating each new step, or having each new step illustrated to him by its identity in kind with the step the next below it? though it be the only mode in which this objection can be answered, yet it seems affronting to remind the objector, of rules so simple as that the complex must even be illustrated by the more simple, or the less scrutible by that which is more subject to our examination.
In reply to No. 2, I first refer to the author's eulogy on Mr. Hunter, p. 163, in which he is justly extolled for having "surveyed the whole system of organized beings, from plants to man:" of course, therefore, as a system; and therefore under some one common law. Now in the very same sense, and no other, than that in which the writer himself by implication compares himself as a man to the dermestes typographicus, or the fucus scorpioides, do I compare the principle of Life to magnetism, electricity, and constructive affinity,—or rather to that power to which the two former are the thesis and antithesis, the latter the synthesis. But if to compare involve the sense of its etymon, and involve the sense of parity, I utterly deny that I do at all compare them; and, in truth, in no conceivable sense of the word is it applicable, any more than a geometrician can be affirmed to compare a polygon to a point, because he generates the line out of the point. The writer attributes to a philosophy essen-
