"If we knew the cause of life...."
"We don't know the cause of anything ... we get to one cause and wonder what caused it. We never know the first cause, and if we found it we'd ask what caused it. Everything goes around in circles. There's the carbon-nitrogen-hydrogen cycle that makes the sun hot—elements change and get back to where they started, losing just a little energy. That energy goes out into space, loses velocity and becomes matter, matter forms suns. Maybe life is part of the merry-go-round. Maybe energy makes matter, life results from matter; life produces a little energy."
"We're generators, huh?"
"Not exactly. Did you ever study a dynamo, Oakey? It doesn't make energy, it converts one form into another form, the stuff we call electricity. But it seems to do it intelligently. Supposing your generator makes a kilowatt of power and you're lighting a string of light bulbs with it. There's ten bulbs, each using 100 watts of power, but some economical so-and-so comes along and turns out five of them. You'd expect the generator to get all fouled up, or maybe burn out some wires, but it goes along at the same speed and makes just 500 watts of power, no more, no less. Dynamos are like that, they never waste their output."
"Is that life?"
"In a way it is," said Al. "Like I said, we're not generators, but life may be just a process of making a little energy. We make just enough to keep the merry-go-round going. Then something goes wrong. We start making more than we should. We get overcharged, like a battery. The energy has to go somewhere, so we start shooting sparks."
Oakey laughed. "Your theories by-pass some of nature's laws and they would make a logician take to a sick bed, but they sound good." He turned his eyes on the chronometer a moment. "What fouls up the safety valve, as long as we're mixing metaphors?"
"Maybe we've got more than life," said Al. "We've got emotions, consciousness and a lot of things that life in general doesn't have. But you and I can control our emotions. We're cold-blooded. I just shot a friend, your friend too and you let me do it. Our cold-blooded common sense told us it was the thing to do. We have to stomp out the Quinnies before we land on the Green Planet. If you get the disease, I'll kill you, just like I killed Joe. If I get it, you'll kill me—"
"No, commander. I won't."