In connection with this subject Dr. Mivart takes occasion to allude to Professor Helmholtz’s method of disproving the absoluteness of truth. He supposes
“beings living and moving along the surface of a solid body, who are able to perceive nothing but what exists on this surface, and insensible to all beyond it.…
If such beings lived on the surface of a sphere, their space would be without a limit, but it would not be infinitely extended; and the axioms of geometry would turn out very different from ours, and from those of the inhabitants of a plane. The shortest lines which the inhabitants of a spherical surface could draw would be arcs of greater circles,” etc.
We have quoted enough from the professor to indicate the drift of his objection. He concludes: “We may résumé the results of these investigations by saying that the axioms on which our geometrical system is based are no necessary truths.” Such is the sorry mode of reasoning adopted by an eminent man of science in establishing a conclusion so subversive of the principles of science. Is it not evident that, no matter what name the inhabitants of the sphere described by Helmholtz might bestow on the “arcs of great circles,” these still would be “arcs,” and as such those beings would perceive them? As showing the lack of uniformity of views which prevail among men of science when it is question of super-sensible cognitions, Mr. Mill rushes to the opposite extreme from Herbert Spencer, and holds that there is nothing to prevent us from conceiving 2×2 = 5. In this arraignment of Spencer’s faulty view of the basis of certainty, Dr. Mivart proceeds with care and acumen, and adroitly pits his antagonists against each other, or invokes their testimony in support of his own views as against themselves.
The other point of interest in this chapter is the author’s refutation of Mr. Lewes’ conception of reasoning. In his Problems of Life and Mind Mr. Lewes reduces the process of reasoning to mere sensible associations, and entirely overlooks
the force and significance of the ergo. He says: “Could we realize all the links in the chain” (of reasoning) “by reducing conceptions to perceptions, and perceptions to sensibles, our most abstract reasonings would be a series of sensations.” This certainly is strange language for a psychologist, and forcibly demonstrates the hold Locke’s sensism still holds over the English mind. If we can conceive of a series of sensations in which the form of a syllogism does not enter—and we experience such many times daily—then surely there is something more in a train of reasoning than a mere series of sensations, and that is the intellectual act of illation denoted by ergo. Throughout this strange philosophism there runs an endeavor to debase man’s intellect and reduce it to the level of mere brutish faculties. The dignity of our common manhood is made the target of Spencer’s speculation and Mill’s subtle reveries, while the grand work of the church which lifted us out from the slough of barbarism is being gradually undone. We must indeed congratulate Dr. Mivart upon having led the way in grappling with the difficulties with which scientific transcendentalism bristles, and on having rent the net in which error strives to hold truth in silken dalliance.
We come now to the most difficult and important chapter in the book—viz., that pertaining to the existence of the external world. We would premise, before entering upon an analysis of this chapter, that nothing short of a slow and careful perusal of it in the author’s language can convey to the reader a full impression of the difficulty and subtlety which attend the terms of the controversy as waged tripartitely between Herbert Spencer, Mr.
Sidgwick, and the author. The statement of the proposition is simple enough, viz.:
“The real existence of an external world made up of objects possessing qualities such as our faculties declare they possess, cannot be logically denied, and may be rationally affirmed.”
The terms of this proposition differ but little from those in which argument is usually made in support of the reality of external objects, but with Dr. Mivart it serves as the text of a refutation of Mr. Spencer’s theory of “transfigured realism.” Mr. Spencer stoutly professes his belief in the realism of the external world, but distinguishes his conception of it from the common crude realism of the majority as having been by him filtered through the intellect, and based, not on the direct data of the senses, but on these as interpreted by the mind. According to him, “what we are conscious of as properties of matter, even down to its weight and resistance, are but subjective affections produced by objective agencies which are unknown and unknowable.” Divested of an involved and trying terminology, Mr. Spencer’s theory amounts to this: The mind under the experience of a sensation is irresistibly borne to admit that it is not itself the active agent concerned in its production; for sensation as a “passing state of consciousness” is not accompanied by that other “passing state of consciousness” which exhibits the mind to itself as spontaneously generating the sensation in question. Therefore that sensation is derived ab extra; therefore its cause, unknown or unknowable, is something outside of the mind—i.e., has an objective reality. It is a sort of game of blind man’s buff between the