of experiment, who is to be considered, the thinker whose aims and works give character to the age.
Attempts have been made from time to time by men who have felt themselves masters of the thought and learning of their era to bring these results together and unify them under some comprehensive term. Thus Herder in his "Ideas for the History of the Human Race" emphasizes Humanity as the proper subject of study, Humanity in the large all-embracing sense. To Hegel it was the Geist, or the spirit of an age which deserves attention. Lotze, a philosopher of great repute not long since deceased, believing that men are living in that sphere of the cosmos of which Humboldt wrote, directed the thought of his time to man as the chief figure of the universe, the microcosmus in the cosmos. Herbert Spencer, without denying the existence of the unknowable or the absolute, testified to his belief in the unity of all things by the prominence he gives in his writings to the social organism. This organism he admits may be, probably is, under the control of an intelligent power but of which we can, he thinks, have no trustworthy knowledge. In these efforts to find some single expression under which all knowledge may be grouped and estimated at its real value, the tendency of the age toward unity is seen. What is desired and sought for is some theory which may be characterized by a single term by means of which whatever is can be explained, or its meaning clearly set forth. Humboldt in the cosmos sought to describe and explain the striking features of the physical world from the standpoint of a philosophical traveler. Hegel wrote as an idealistic philosopher, as a descendant, though not a follower of Kant. Herder and Lotze were, influenced by the poetry and the current philosophy of their time, while men like Du Bois Reymond, denying that they were under the influence of any guiding star, adopted as their motto Ignoramus, Ignorabimus, Dubetemus, Laboremus. Haeckel as a pronounced materialist is still trying to guess the meaning of the riddles of the universe. In his position he is valiantly and ably opposed by the spiritualist, Sir Oliver Lodge.
It is not easy to find a road which will take one through the diversified and often confused thought of a single age, or a race, to say nothing of the thought of all the ages. Here and there events are prominent enough to characterize a century, or several centuries. Such was the case in the history of the Hebrew people, the early centuries of the Christian church, the century in which the power of the Pope culminated, the age of the revival of learning, the era of the reformation, the period of the French revolution, the beginning of the still continuing tendency among the more intelligent nations toward self-government, the most successful example being our own republic. Yet as a thinking age the nineteenth century has no distinguishing title. If it had we might have been spared such philosophies as those of the