goal may be attained. Development is all that is required, and not a change of quality. There need be no absolute breach of continuity between us and our loftier brothers yet to come. We have guarded ourselves against saying that the inferring of thought from material combinations and arrangements would be an inference _à priori_. The inference meant would be the same in kind as that which the observation of the effects of food and drink upon the mind would enable us to make, differing only from the latter in the degree of analytical insight which we suppose attained. Given the masses and distances of the planets, we can infer the perturbations consequent on their mutual attractions. Given the nature of a disturbance in water, air, or ether--from the physical qualities of the medium we can infer how its particles will be affected. Here the mind runs with certainty along the line of thought which connects the phenomena, and from beginning to end finds no break in the chain. But when we endeavour to pass by a similar process from the phenomena of physics to those of thought, we meet a problem which transcends any conceivable expansion of the powers which we now possess. We may think over the subject again and again, but it eludes all intellectual presentation. We stand at length face to face with the Incomprehensible. The territory of physics is wide, but it has its limits from which we look with vacant gaze into the region beyond. Whence come we; whither go we? The question dies without an answer--without even an echo--upon the infinite shores of the Unknown. Let us follow matter to its utmost bounds; let us claim it in all its forms to experiment with and to speculate upon. Casting the term ‘vital force’ from our vocabulary, let us reduce, if we can, the visible phenomena of life to mechanical attractions and repulsions. Having thus exhausted physics, and reached its very rim, the real mystery still looms beyond us. We have, in fact, made no step towards its solution. And thus it will ever loom--ever beyond the bourne of knowledge--compelling the philosophies of successive ages to confess that We are such stuff As dreams are made of, and our little life Is rounded with a sleep. FOOTNOTES: [Footnote 1: One of my critics remarks, that he does not see the wit of calling Goethe’s ‘Farbenlehre’ and Bain’s ‘Logic,’ ‘two volumes of poetry.’ Nor do I.] [Footnote 2: Induction, page 422.] [Footnote 3: This glass, by reflected light, had a colour ‘strongly resembling that of a decoction of horse-chestnut bark.’ Curiously enough Goethe refers to this very decoction:--‘Man nehme einen Streifen frischer Rinde von der Rosskastanie, man stecke denselben in ein Glas Wasser, und in der kürzesten Zeit werden wir das vollkommenste Himmelblau entstehen sehen.’--Goethe’s _Werke_, b. xxix. p. 24.]