The mystical temperament is little enough popular in this workaday modern world of ours. The mystic, we feel, comes to us discounted from the start; he should in all decency make constant apologies for his existence. In a practical age of machinery he is an anomaly, an anachronism. He must meet the direct challenge of the scientist, who guards every approach to the doors of truth and holds the keys of its citadel. Any thinker who gets into the fold by another way is a thief and a robber. The mystic must answer that most heinous of all charges,--of being unscientific. By tradition he is even hostile to science. For his main interest is in wonder, and science by explaining things attacks the very principle of his life. It not only diminishes his opportunities for wonder, but threatens to make him superfluous by ultimately explaining everything. The scientist may say that there is no necessary antithesis between explanation and that beautiful romance of thought we call wonder. The savage, who can explain nothing, is the very creature who has no wonder at all. Everything is equally natural to him. Only a mind that has acquaintance with laws of behavior can be surprised at events. The wonder of the scientist, however, although it be of a more robust, tough-minded variety, is none the less wonder. A growing acquaintance with the world, an increasing at-homeness in it, is not necessarily incompatible with an ever-increasing marvel both at the beautiful fitness of things and the limitless field of ignorance and mystery beyond. So the modern mystic must break with his own tradition if he is to make an appeal to this generation, and must recognize that the antithesis between mystic and scientific is not an eternally valid one. It is just through realization of this fact that Maeterlinck, the best of modern mystics, makes his extraordinary appeal. For, as he tells us, the valid mystery does not begin at the threshold of knowledge but only after we have exhausted our resources of knowing. His frank and genuine acceptance of science thus works out a _modus vivendi_ between the seen and the unseen. It allows many of us who have given our allegiance to science to hail him gladly as a prophet who supplements the work of the wise men of scientific research, without doing violence to our own consciences. For the world is, in spite of its scientific clamor, still far from ready really to surrender itself to prosaicness. It is still haunted with the dreams of the ages--dreams of short roads to truth, visions of finding the Northwest passage to the treasures of the Unseen. Only we must go as far as possible along the traveled routes of science.