Man has not only for thousands of years had the spirit of immortality, of keeping his voice filed away if any one wanted it on the earth, forever, but he has had all the other spirits or ghosts of his mightier self. He has had the spirit of being imperious and wilful with the sea, of faring forth on a planet and playing with oceans, and now he has worked out the details in ocean liners, in boats that fly up from the water, and in boats which dive and swim beneath the sea. For thousands of years he has had the spirit of the locomotive working through, troops of runners or of dim men groping defiantly with camels through deserts, or sweeping on on horses through the plains, and now with his banners of steam at last he has great public trains of cars carrying cities.
For hundreds of years man has had the spirit of the motor-car—of having his own private locomotive or his own special train drive up to his door—the spirit of making every road his railway. For a great many years he has had the spirit of the wireless telegraph and of using the sky. Franklin tried using the sky years ago but all he got was electricity. Marconi knew how better. Marconi has got ghosts of men's voices out of the clouds, has made heaven a sounding board for great congregations of cities, and faraway nations wrapped in darkness and silence whisper round the rolling earth. Man has long had the spirit of defying the seas. Now he has the technique and the motor-boat. He has had the spirit of removing oceans and of building huge, underground cities, the spirit of caves in the ground and mansions in the sky, and now he has subways and skyscrapers. For a thousand years he has had the spirit of Christ and now there is Frederick Taylor, Louis Brandeis, Westfield Pure Food, Doctor Carrel, Jane Addams, and Filene's Store. Vast networks—huge spiritual machines of goodness are crowding and penetrating to-day, fifteen pounds to the square inch, the atmosphere of the gospel into the very core of the matter of the world, into the everyday things, into the solids of the lives of men.
It takes two great spirits of humanity to bring a great truth or a new goodness into this world; one spirit creates it, the other conceives it, gathers the earth about it and gives it birth. These two spirits seem to be the spirits of the poet and the scientist.
We are taking to-day, many of us, an almost religious delight in them both. We make no comparisons.
We note that the poet's inspiration comes first and consists in saying something that is true, that cannot be proved.
A few people with imagination, here and there, believe it.
The scientist's inspiration comes second and consists in seeing ways of proving it, of making it matter of fact.
He proves it by seeing how to do it.
Crowds believe it.