There is, however, this difference—the external senses have intrinsic powers of adaptation so ready, and perfect, as scarcely to be taken by surprise by any natural transition. The moral and intellectual powers do not appear to possess this electric activity; but require slower gradations of impression, which, by some law in the progress of human affairs, are (as the rule) mercifully supplied. In his own lessons, whenever he met with any _apparent_ imperfection, and wished to impress its _real_ beauty of adaptation, Abernethy was very fond of what he termed his argumentum ex absurdo. He would suppose various other arrangements, and point out in succession their unfitness for the purposes required. Tried in the same manner, we can see nothing better than that which really happened. If Abernethy met with coldness where he expected warmth—and dispute and discussion where he might have calculated on grateful concession,—how well-fitted must have been that reverence and affection which longingly awaited his retirement at home. If the greatest worldly success, in that occupation in which he had always felt most pleasure, was still not without its dark lights—shadowing forth what the world really is,—what could he have had better to concentrate his views on those substantial sources of comfort, of which he had long believed and estimated the value, and on which he was contented to repose. It had always been a favourite expression of his, when in any doubt or difficulty: "Well, I will consult my pillow, and we shall see." We believe that pillow seldom flattered. [Footnote 76: It was accordingly named the Apteryx, or wingless, from the Greek Alpha and Pterux.]