"A game of chess begins with only twenty playable moves to choose from. At every move the choice available to the player is restricted, and yet, the number of legitimate positions that the board could assume after only ten moves is astronomical. Imagine, then, the number of permutations that could arise when the game continues for a billion moves and at each move the player has a billion choices open to him. This is the game of evolution. To suppose that two such independent sequences could result in end products that are identical would surely be demanding too much of our credulity. The laws of chance and statistics are quite firm when applied to sufficiently large numbers of samples. The laws of thermodynamics, for example, are nothing more than expressions of the probable behavior of gas molecules, yet the numbers involved are so large that we feel quite safe in accepting the postulates as rigid rules; no significant departure from them has ever been observed. The probability of the parallel line of evolution that you suggest is less than the probability of heat flowing from the kettle to the fire, or of all the air molecules in this room crowding into one corner at the same time, causing us all to explode spontaneously. Mathematically speaking, yes—the possibility of parallelism is finite, but so indescribably remote that we need consider it no further."

A young electronics engineer took the argument up at this point.

"Couldn't God get a look in?" he asked. "Or at least, some kind of guiding force or principle that we don't yet comprehend? Couldn't the same design be produced via different lines in different places?"

Danchekker shook his head and smiled almost benevolently.

"We are scientists, not mystics," he replied. "One of the fundamental principles of scientific method is that new and speculative hypotheses do not warrant consideration as long as the facts that are observed are adequately accounted for by the theories that already exist. Nothing resembling a universal guiding force has ever been revealed by generations of investigation, and since the facts observed are adequately explained by the accepted principles I have outlined, there is no necessity to invoke or invent additional causes. Notions of guiding forces and grand designs exist only in the mind of the misguided observer, not in the facts he observes."

"But suppose it turns out that Charlie came from somewhere else," the metallurgist insisted. "What then?"