32: Why You Are, How You See

The Moon-being concludes his discussion of existential contingency and segues neatly into an application of atomic theory to sensation. With a little information about photons and light sources he’d be quite up to date. Meanwhile, Cyrano wants to know how this helps him comb his hair...

“You are amazed that matter can form a man when matter is all mixed up at random and so many things go into making a person. But do you not realize that before matter forms someone it has also stopped along the way to make a stone, lead, coral, a flower, or a comet because there was too much or too little of it to make a human being? No wonder, then, that an infinite amount of incessantly moving and changing matter makes up the few animals, vegetables and minerals that we see. No wonder, either, that if you throw dice a hundred times, they will all show the same numbers at some point.

“This movement of matter, then, could not fail to produce something, and whatever it is will always be admired by the unthinking person who does not realize how close it came to not being made. The great river makes a water mill turn or winds the springs of a clock, and the little brook only flows and sometimes overflows. You will not say that the river has a mind, because you know it has encountered on its way the masterworks built to perform all these fine feats. If a mill were not located on the river, the river would not grind wheat. If the river did not encounter a clock, it would not toll the hours. And if the little brook I mentioned encountered the same things, it would perform the same miracles.

“The same is true of the fire that supplies its own motion. When it has found the organs whose motion is necessary to reason, it reasons. When it has found organs suited for sensation, it senses. When it has found those suited for growth, it grows. This fire or soul enables man to see, but if you blind his eyes, he will cease to see. Likewise, the large river will no longer toll the hours if the clock is torn down.

“Finally, these primordial and indivisible atoms form a unity that easily encompasses the most troublesome difficulties of physics. With these little bodies I can very easily explain something that no one has yet been able to conceive: how the senses work. Let us begin with sight: it deserves to come first because it is the hardest to comprehend.

“Sight occurs, I imagine, when the membranes of the eye, whose openings are like those of glass, emit the energetic particles called visual rays. These rays are stopped by an opaque object, which causes them to return to their origin. The image we see is formed by the reflecting object; the image itself is but an infinite number of little bodies that are emitted continually and uniformly from whatever we are looking at, and they reach our eye.

“Of course you will object that glass is an opaque and very dense substance and that instead of reflecting these other little bodies it lets itself be pierced by them. My answer is that the pores of glass are shaped the same as these energetic atoms that traverse it. Just as a wheat sieve is not useful for sifting oats, nor an oat sieve for sifting wheat, a pine box may be thin enough to let sound escape but not be penetrable by sight. We can see through a piece of crystal, because it is transparent, but we cannot hear through it.”

I could not keep from interrupting: “But how, sir, by those principles, can you explain how we can use a mirror when we comb our hair?”

“Very easily,” he answered. “Imagine that these visual rays from our eye traverse the glass and are reflected by a non-transparent body on the other side. They go back out the way they came in. They find the little bodies that have left the eye alighting uniformly on the mirror and bring them back to our eyes. Our imagination, which is more energetic than the other faculties of our mind, attracts the subtlest of them and makes a miniature portrait.”

If Cyrano had a child who asked him, “Daddy, where did I come from?” would he reply, “From a roll... um... of the dice, my dear”? The response would be better suited to an adult; a child is looking for existential reassurance, not scientific accuracy. The “visual rays” are a mistaken notion, of course; but if they are disregarded, the Moon-being’s explanation of sight shows that the door is now open to the advances in optics that will be made in the next two centuries.