the fundamental ideas of the science, such as Vital Forces, Nutrition, Reproduction, and the like. We had before us at some length, in the _History of Scientific Ideas_, a review {183} of the opposite opinions which have been advanced on this subject; and we attempted in some degree to estimate the direction in which these ideas are permanently settling. But without attaching any importance to this attempt, the account there given may at least serve to show, how important a share in the past progress of this subject the _discussion_ of its Fundamental Ideas has hitherto had. [Note 22\3: _Hist. Ind. Sc._ b. xiii. c. 6.] 4. There is one reflexion which is very pointedly suggested by what has been said. The manner in which our scientific ideas acquire their distinct and ultimate form being such as has been described,--always involving much abstract reasoning and analysis of our conceptions, often much opposite argumentation and debate;--how unphilosophical is it to speak of abstraction and analysis, of dispute and controversy, as frivolous and unprofitable processes, by which true science can never be benefitted; and how erroneous to put such employments in antithesis with the study of facts! Yet some writers are accustomed to talk with contempt of all past controversies, and to wonder at the blindness of those who did not _at first_ take the view which was established _at last_. Such persons forget that it was precisely the controversy, which established among speculative men that final doctrine which they themselves have quietly accepted. It is true, they have had no difficulty in thoroughly adopting the truth; but that has occurred because all dissentient doctrines have been suppressed and forgotten; and because systems, and books, and language itself, have been accommodated peculiarly to the expression of the accepted truth. To despise those who have, by their mental struggles and conflicts, brought the subject into a condition in which errour is almost out of our reach, is to be ungrateful exactly in proportion to the amount of the benefit received. It is as if a child, when its teacher had with many trials and much trouble prepared a telescope so that the vision through it was distinct, should wonder at his stupidity in pushing the tube of the eye-glass out and in so often. {184}