We can now reply to the objection which we have placed at the beginning of this chapter: "How can the solar rays, being material substances, convey animated germs, which are immaterial substances?"
When the physicists professed Newton's theory of the nature of light, in the theory of emission, it was necessary to regard light, and, consequently the solar rays, which produce it, as material bodies.
But science has now rejected this theory, and replaced it by the theory of undulation, founded by Malus, Fresnel, Ampère, and all the constellation of great physicists and mathematicians of the commencement of this century. Facts, collected on every side, prove that the solar rays are not matter which transports itself from the sun to the earth, but that light, like heat, results from a primitive disturbance produced by the sun upon the ether, which is spread over all space. This disturbance communicates itself from molecule to molecule, from the planetary ether down to us, and produces the phenomena of light and heat. We cannot here develop at greater length, or explain more scientifically, the theory of undulations, which will be found sufficiently demonstrated in works on physics. We merely desire to prove that, according to the principles of modern science, the solar rays are not material bodies, but that they result from a simple vibration of the planetary ether. If, then, the rays of the sun are not material substances, there can be no difficulty in admitting that these rays (immaterial substance) are the bearers of the animated germs, which are immaterial substance.
If we be driven to a closer definition of the problem, if we be asked to explain with greater precision how these immaterial germs journey through space, we reply that we must guard against the mania for insisting on everything being explained. Absolute explanation is forbidden to the limit of our intelligence. We are forced to confess our powerlessness whenever we try to explain the phenomena of nature rigorously. What is the true cause of the fall of bodies, of the gravitation of the stars, of electricity, of heat? What is the cause of the circulation of our blood, of the beating of our hearts? The deepest obscurity veils the primary causes of these phenomena, which we all behold every day; and the more earnestly we desire to penetrate the secret essence, the more the darkness deepens in our minds. Since the time of Newton, the physicists have laid down a wise and excellent principle. They have agreed to study the laws of physical phenomena with sedulous care, to measure with exactness the effects of heat, weight, electricity, or light, but, also, never to disquiet themselves by researches into the causes of these phenomena. The more we learn, the further we advance in the knowledge of the universe and its laws, the more we become convinced that man knows absolutely nothing about first causes, that he ought to esteem himself happy in knowing the laws according to which the effects of these first causes manifest themselves; that is to say, the physical and vital actions which are visible to us, but that he ought, in the interests of his own peace of mind, to lay down a rule that he would never seek to know the wherefore of things. Pliny, speaking of first causes, said: "Latent in majestate mundi," ("They are hidden in the majesty of the world.") The thought is as fine as the phrase is eloquent. Let us, then, leave to nature her secrets, and, if we are led to believe that the sun sheds animated germs upon the earth and the planets, let us not try to penetrate further into the essence of this mysterious phenomenon. Let us not ask of the earth why she turns, the stone why it falls, the tree why it grows, our hearts why they beat—nor the rays of the sun why they produce life on earth, and immortality in the heavens.
CHAPTER THE TWENTIETH.
PRACTICAL RULES RESULTING FROM THE FACTS AND PRINCIPLES DEVELOPED IN THIS WORK.—THE ENNOBLING OF THE SOUL BY THE PRACTICE OF VIRTUE, BY SEEKING TO KNOW, THROUGH SCIENCE, NATURE AND ITS LAWS.—THE RENDERING OF PUBLIC WORSHIP TO THE DIVINITY.—THE MEMORY OF THE DEAD TO BE RETAINED.—WE OUGHT NOT TO FEAR DEATH.—DEATH IS ONLY AN UNFELT TRANSITION FROM ONE STATE TO ANOTHER, IT IS NOT A TERMINATION, BUT A METAMORPHOSIS.—THE IMPRESSIONS OF THE DYING.—THEY WHOM THE GODS LOVE DIE YOUNG.—REUNION WITH THOSE WHO HAVE GONE BEFORE.
