This language of life spoke indeed in the programme of another plan which seemed also to be suggested by the character of the Exposition. The St. Louis Fair desired not merely to look backward and to revive the historical interest in the Louisiana purchase, but its first aim seemed to be to bring into sharp relief the factors which serve to-day the practical welfare and the achievements of human society. If all the scholars of all sciences were to convene under one flag, would it not thus seem most harmonious with the occasion, if, as the one controlling topic, the question were proposed, "What does your science contribute to the practical progress of mankind?" No one can deny that such a formulation would fit in well with the lingering thoughts of every World's Fair visitor. Whoever wanders through the aisles of exhibition palaces and sees amassed the marvelous achievements of industry and commerce, and the thousand practical arts of modern society, may indeed turn most naturally to a gathering of scholars with the question, "What have you to offer of similar import?" All your thinking and speaking and writing, are they merely words on words, or do you also turn the wheels of this gigantic civilization? Such a question would give a noble opening indeed to almost every science. Who would say that the opportunity is confined to the man of technical science? Does not the biologist also prepare the achievements of modern medicine, does not the mathematician play his most important rôle in our mastery over stubborn nature, do we not need language for our social intercourse, and law and religion for our practical social improvement? Yes, is there any science which has not directly or indirectly something to contribute to the practical development of the modern man and his civilization? All this is true, and yet the perspective of this truth, too, appears at once utterly distorted if we take the standpoint of science itself. The one end of knowledge is to reach the truth. The belief in the absolute value of truth gives to it meaning and significance. This value remains the controlling influence even where the problem to be solved is itself a practical one, and the spirit of science remains thus essentially theoretical even in the so-called applied sciences. But incomparably more intense in that respect is the spirit of all theoretical disciplines. Philosophy and mathematics, history and philology, chemistry and biology, astronomy and geology, may be and ought to be helpful to practical civilization everywhere; and every step forward which they take will be an advance for man's practical life too. And yet their real meaning never lies in their technical by-product. It is not the scholar who peers in the direction of practical use who is most loyal to the deepest demand of scholarship, and every relation to practical achievement is more or less accidental or even artificial for the real life interests of productive scholarship.