* * * * * Returning to the idea of psychical mechanism, he admits that “it is itself so obscure that we can hardly form any idea concerning it,” {139a} and then goes on to claim for it that it explains a great many other things. This must have been the passage which Mr. Sully had in view when he very justly wrote that Von Hartmann “dogmatically closes the field of physical inquiry, and takes refuge in a phantom which explains everything, simply because it is itself incapable of explanation.” * * * * * According to Von Hartmann {139b} the unpractised animal manifests its instinct as perfectly as the practised. This is not the case. The young animal exhibits marvellous proficiency, but it gains by experience. I have watched sparrows, which I can hardly doubt to be young ones, spend a whole month in trying to build their nest, and give it up in the end as hopeless. I have watched three such cases this spring in a tree not twenty feet from my own window and on a level with my eye, so that I have been able to see what was going on at all hours of the day. In each case the nest was made well and rapidly up to a certain point, and then got top-heavy and tumbled over, so that little was left on the tree: it was reconstructed and reconstructed over and over again, always with the same result, till at last in all three cases the birds gave up in despair. I believe the older and stronger birds secure the fixed and best sites, driving the younger birds to the trees, and that the art of building nests in trees is dying out among house-sparrows. * * * * * He declares that instinct is not due to organisation so much as organisation to instinct. {140} The fact is, that neither can claim precedence of or pre-eminence over the other. Instinct and organisation are only mind and body, or mind and matter; and these are not two separable things, but one and inseparable, with, as it were, two sides; the one of which is a function of the other. There was never yet either matter without mind, however low, nor mind, however high, without a material body of some sort; there can be no change in one without a corresponding change in the other; neither came before the other; neither can either cease to change or cease to be; for “to be” is to continue changing, so that “to be” and “to change” are one. * * * * *