Now, we submit that this method of constructing a philosophy of Nature is radically vicious, and diametrically opposed to the only legitimate, the only possible way of attaining to sound knowledge. He is not content to tell us _what is_ the order of things; he aspires, forsooth, to show what the order of things _must be_. We have no wish to disparage Metaphysical Science; it has a natural root in human reason, and a legitimate domain in the ample territory of human thought; but we protest against any attempt to extend it beyond its proper boundaries, or to apply it to subjects which belong to the province of experience and observation. The schemes which have been recently broached in Germany, and imitated in France, for constructing, at one time, a deductive Psychology, at another a deductive Physics, at a third a deductive Ethics, at a fourth a deductive Theory of Progress, at a fifth a deductive History of Religion, afford more than sufficient evidence that hitherto the spirit of the Baconian philosophy has been little understood, and still less appreciated, by our continental neighbors; and that the efforts of the highest genius have been sadly frustrated, in attempting the impracticable task of extracting from mere reason that knowledge which can only be acquired in the school of experience. This is our _second_ objection. 3. The system of Spinoza is vicious, because it applies a mere abstraction of the human mind to account for whatever is real and concrete in the universe. We have no sympathy with those who rail at all abstract ideas, as if they were imaginary essences or mere illusions; we recognize the faculty of abstraction as one of the wisest provisions of Nature, and one of the most useful powers belonging to the mind of man,--a power which comes into action with the first dawn of infant intelligence, and is only matured as reason rises into manhood, till it becomes the internal spring of all Philosophy and Science. Nor do we hold that an abstract idea is necessarily an unreality, or a mere negation; for, without reviving the controversy between the Nominalists and Realists, or pronouncing any decision on the intricate questions which that controversy involved, we may say, in general terms, that the idea of a circle, of a square, or of a triangle, is neither unreal nor negative, but a very positive, and, withal, intelligible thing. It is the idea of that which is essential to the nature of each of these figures respectively, and common to all possible figures of the same class, whatever may be their accidental varieties, whether in point of dimension or form. And so the idea of Being or Substance, although it be highly abstract, is not necessarily unreal or negative; it is the idea of _existence_, or of that which is common to everything that _is_, abstraction being made of every diversity by which one being is distinguished from another. Conscious that we ourselves exist, and