Let me confess to the diffidence with which I find myself standing here to-day. When the invitation of your committee reached me last fall, the simple truth is that I accepted it as most men accept a challenge,--not because they wish to fight, but because they are ashamed to say no. Pretending in my small sphere to be a teacher, I felt it would be cowardly to shrink from the keenest ordeal to which a teacher can be exposed,--the ordeal of teaching other teachers. Fortunately, the trial will last but one short hour; and I have the consolation of remembering Goethe's verses,-- "Vor den Wissenden sich stellen, Sicher ist 's in allen Fällen,"-- for if experts are the hardest people to satisfy, they have at any rate the liveliest sense of the difficulties of one's task, and they know quickest when one hits the mark. Since it was as a teacher of physiology that I was most unworthily officiating when your committee's {112} invitation reached me, I must suppose it to be for the sake of bringing a puff of the latest winds of doctrine which blow over that somewhat restless sea that my presence is desired. Among all the healthy symptoms that characterize this age, I know no sounder one than the eagerness which theologians show to assimilate results of science, and to hearken to the conclusions of men of science about universal matters. One runs a better chance of being listened to to-day if one can quote Darwin and Helmholtz than if one can only quote Schleiermacher or Coleridge. I almost feel myself this moment that were I to produce a frog and put him through his physiological performances in a masterly manner before your eyes, I should gain more reverential ears for what I have to say during the remainder of the hour. I will not ask whether there be not something of mere fashion in this prestige which the words of the physiologists enjoy just now. If it be a fashion, it is certainly a beneficial one upon the whole; and to challenge it would come with a poor grace from one who at the moment he speaks is so conspicuously profiting by its favors. I will therefore only say this: that the latest breeze from the physiological horizon need not necessarily be the most important one. Of the immense amount of work which the laboratories of Europe and America, and one may add of Asia and Australia, are producing every year, much is destined to speedy refutation; and of more it may be said that its interest is purely technical, and not in any degree philosophical or universal.