Ever since the beginning of human history there have been people who puzzled their brains about the reasons of things. Why things are as they are, whence we came, and whither we are going are some of the perplexing questions they have tried to answer. Some men have given all their lives to the study of these problems as a single occupation or profession. Among the ancient Greeks, who were a very intellectual nation, such men were quite numerous and were held in great esteem as teachers. They were called philosophers, that is, lovers of wisdom, and this word has been passed down to our own times in various modern languages.

In the passing of the centuries men found more and more subjects to think about. Some studied the movements of the stars and tried to discover if they had any influence in human affairs. These men were called astrologers, and they drew plans, known as horoscopes, mapping out the future destiny of persons as revealed by the position of the constellations. There were other men who examined the various substances of which the earth is composed, putting them together to make new things. These were alchemists, and their great ambition was to find some preparation which would change baser metals into gold. This hoped-for preparation was spoken of as the "philosopher's stone."

Now modern learning has changed these vague experiments into exact science; astronomy has replaced astrology, and chemistry has taken the place of alchemy. Nevertheless these changes were brought about only very gradually, and in the 17th century, when Rembrandt lived and painted this picture, a great stir was made by the new ideas of astronomy taught by Galileo in Italy, and the new discoveries in chemistry made by Van Helmont in Belgium. Many philosophers still held to the old beliefs of astrology and alchemy.

It is not likely that Rembrandt had any one philosopher in mind as the subject of his picture. That his philosopher is something of a scholar, we judge from the table at which he sits, littered with writing materials. Yet he seems to care less for reading than for thinking, as he sits with hands clasped in his lap and his head sunk upon his breast. He wears a loose, flowing garment like a dressing-gown, and his bald head is protected by a small skull cap. His is an ideal place for a philosopher's musings. The walls are so thick that they shut out all the confusing noise of the world. A single window lets in light enough to read by through its many tiny panes. It is a bare little room, to be sure, with its ungarnished walls and stone-paved floor, but if a philosopher has the ordinary needs of life supplied he wants no luxuries. He asks for nothing more than quiet and uninterrupted leisure in which to pursue his meditations.

The Louvre, Paris

Our philosopher is well taken care of; for while his thoughts are on higher things and eternal truths, an old woman is busy at the fire in the corner. Evidently she looks after the material and temporal things of life. She kneels on the hearth and hangs a kettle over the cheerful blaze. The firelight glows on her face and gleams here and there on the brasses hanging in the chimney-piece above. Here is promise of something good to come, and when the philosopher is roused from his musings there will be a hot supper ready for him.

There are two mysteries in the room which arouse our curiosity. In the wall behind the philosopher's chair is a low, arched door heavily built with large hinges. Does this lead to some subterranean cavern, and what secret does it contain? Is it a laboratory where, with alembic and crucible, the philosopher searches the secrets of alchemy and tries to find the "philosopher's stone?" Is some hid treasure stored up there, as precious and as hard to reach as the hidden truths the philosopher tries to discover?

At the right side of the room a broad, winding staircase rises in large spirals and disappears in the gloom above. We follow it with wondering eyes which try to pierce the darkness and see whither it leads. Perhaps there is an upper chamber with windows open to the sky whence the philosopher studies the stars. This place with its winding staircase would be just such an observatory as an astrologer would like. Indeed it suggests at once the tower on the hillside near Florence where Galileo passed his declining years.

Our philosopher, too, is an old man; his hair has been whitened by many winters, his face traced over with many lines of thought. Even if his problems have not all been solved he has found rich satisfaction in his thinking; the end of his meditations is peace. The day is drawing to a close. The waning light falls through the window and illumines the philosopher's venerable face. It throws the upper spiral of the stairway into bold relief, and brings out all the beautiful curves in its structure. The bare little room is transfigured. This is indeed a fit dwelling-place for a philosopher whose thoughts, penetrating dark mysteries, are at last lighted by some gleams of the ideal.