"Our sensations require ideas to bind them together; namely, ideas of space, time, number, and the like. If not so bound together, sensations do not give us any apprehension of things or objects. All things, all objects, must exist in space and in time—must be one or many. Now space, time, number, are not sensations or things. They are something different from, and opposed to, sensations and things. We have termed them ideas. It may be said they are relations of things, or of sensations. But granting this form of expression, still a relation is not a thing or a sensation; and therefore we must still have another and opposite element, along with our sensations....
"We are often told that such a thing is a fact—a fact, and not a theory,—with all the emphasis which, in speaking or writing, tone or italics or capitals can give. We see from what has been said, that when this is urged, before we can estimate the truth, or the value of the assertion, we must ask to whom is it a fact? what habits of thought, what previous information, what ideas does it imply, to conceive the fact as a fact? Does not the apprehension of the fact imply assumptions which may with equal justice be called theory, and which are perhaps false theory? in which case the fact is no fact. Did not the ancients assert it as a fact, that the earth stood still, and the stars moved? and can any fact have stronger apparent evidence to justify persons in asserting it emphatically than this had?"—Whewell's Philosophy of the Inductive Sciences, 2nd ed., vol. i., p. 42, seq.
That the solidity of figures is in truth given by mental judgment, has been often proved experimentally; see for examples, Huxley's Elementary Physiology, Lesson x., 13–16. The experiment with a coin, lens and pin, p. 259, is easy as well as conclusive, but Wheatstone's Pseudoscope more surprising to most observers. Compare on this curious subject Brewster's Natural Magic, Letter v.
[169] It is important to bear in mind that, from an admitted incompetency of our faculties to know the absolute, we cannot infer an impossibility of knowing its existence. To know that a thing is, and to know what it is, are two totally distinct degrees and sorts of knowledge. The moment this distinction is stated, every one sees its truth; but many persons omit stating it to themselves when they reason upon these difficult subjects.
Ravaisson, after giving a brief account of Herbert Spencer's opinion, goes on to say: "Comment il y a, au fond de toute connaissance, un absolu, auquel correspond, comme son opposé, le relatif, c'est ce qu'établissait, il y a plus de vingt siècles, contre une doctrine déjà régnante alors de relativité et de mobilité universelles, la dialectique platonicienne, qui fraya le chemin à la metaphysique. Elle faisait plus: elle montrait que par cet absolu seul les relations sont intelligibles, parce qu'il est la mesure par laquelle seule nous les estimons. La métaphysique, entre les mains de son immortel fondateur, fit davantage encore: elle montra que cet absolu, par lequel l'intelligence mesure le relatif, est l'intelligence même. C'est ce que redisait Leibniz, lorsque, à cette assertion, renouvelée de la scolastique par Locke, qu'il n'était rien dans l'intelligence qui d'abord n'eût été dans le sens, il répondait: "sauf l'intelligence," et que, avec Aristote, il montrait dans l'intelligence la mesure supérieure du sens."—Rapport, p. 66.
Ravaisson then gives interesting extracts from Sophie St. Germain, and proceeds to show how Comte, without admitting any self-contemplating intelligence, and thus inferring the possibility of an Absolute, did in fact pursue the idea of Unity, and extended this idea to the universe,—a principle which, if fully grasped, must be fatal to Positive views. "D'accord maintenant avec Platon, Aristote, Leibniz, il déclarait que l'ensemble étant le resultat et l'expression d'une certaine unité, à laquelle tout concourt et se co-ordonne et qui est le but où tout marche, c'est dans cette unité, c'est dans le but, c'est dans la fin ou cause finale qu'est le secret de l'organisme."—Rapport, p. 76.
A special interest attaches to the work of Ravaisson as an authoritative French rating of the philosophic exchange between England and France. It is almost unnecessary to refer for a less abstract account of these relations to the widely known writings of M. Taine.
[170] It should have been stated in the text, as it was in the delivered lecture, that these questions were not forgotten by the eminent Professor. The passages referred to will be found in his eloquent address on the "Scientific use of the Imagination," p. 47, seq., or in his volume of collected Essays, p. 163, seq. The reader may observe that, both in Professor Tyndall's pages and two sentences back in this lecture, Development is spoken of as a process or law in operation. The various kinds of philosophy which may be engrafted on such a law are severally determined by whatever reply is given to the questions above suggested. It would seem inappropriate here to state the possible relations between a law of development and such consequent (or inconsequent) philosophies. Those who wish to consider them the writer may refer to his little volume entitled "Right and Wrong," for a brief discussion of this subject, and more particularly for the results to natural theology.
The following German sketch of an evolution-philosophy may not be without interest:—"Vermöge einer ewigen Kreisbewegung entstehen als Verdichtungen der Luft unzählige Welten, himmlische Gottheiten, in deren Mittelpunkt die cylinderförmige Erde ruht, unbewegt wegen des gleichen Abstandes von allen Punkten der Himmelskugel. Die Erde hat sich aus einem unsprünglich flüssigen Zustande gebildet. Aus dem Feuchten sind unter dem Einfluss der Wärme in stufenweise Entwickelung die lebenden Wesen hervorgegangen. Auch die Landthiere waren anfangs fischartig und haben erst mit der Abtrocknung der Erdoberfläche ihre jetzige Gestalt gewonnen. Die Seele soll Anaximander als luftartig bezeichnet haben."
Anaximander of Miletus was born about B.C. 610. Consequently he ranks early among European theorizers on development. The extract is from Ueberweg's Grundriss, t. 1, p. 40. Cf. Plutarch de Placit. v. 19, and Sympos viii. qu. 8, with Euseb. Præp. Evang. i. 8.