Enlightenment Now: The Case for Reason, Science, Humanism, and Progress

Creationists commonly doctor the Second Law of Thermodynamics to claim that biological evolution, an increase in order over time, is physically impossible. The part of the law they omit is “in a closed system.” Organisms are open systems: they capture energy from the sun, food, or ocean vents to carve out temporary pockets of order in their bodies and nests while they dump heat and waste into the environment, increasing disorder in the world as a whole. Organisms’ use of energy to maintain their integrity against the press of entropy is a modern explanation of the principle of conatus (effort or striving), which Spinoza defined as “the endeavor to persist and flourish in one’s own being,” and which was a foundation of several Enlightenment-era theories of life and mind.⁷

The ironclad requirement to suck energy out of the environment leads to one of the tragedies of living things. While plants bask in solar energy, and a few creatures of the briny deep soak up the chemical broth spewing from cracks in the ocean floor, animals are born exploiters: they live off the hard-won energy stored in the bodies of plants and other animals by eating them. So do the viruses, bacteria, and other pathogens and parasites that gnaw at bodies from the inside. With the exception of fruit, everything we call “food” is the body part or energy store of some other organism, which would just as soon keep that treasure for itself. Nature is a war, and much of what captures our attention in the natural world is an arms race. Prey animals protect themselves with shells, spines, claws, horns, venom, camouflage, flight, or self-defense; plants have thorns, rinds, bark, and irritants and poisons saturating their tissues. Animals evolve weapons to penetrate these defenses: carnivores have speed, talons, and eagle-eyed vision, while herbivores have grinding teeth and livers that detoxify natural poisons.

And now we come to the third keystone, information.⁸ Information may be thought of as a reduction in entropy—as the ingredient that distinguishes an orderly, structured system from the vast set of random, useless ones.⁹ Imagine pages of random characters tapped out by a monkey at a typewriter, or a stretch of white noise from a radio tuned between channels, or a screenful of confetti from a corrupted computer file. Each of these objects can take trillions of different forms, each as boring as the next. But now suppose that the devices are controlled by a signal that arranges the characters or sound waves or pixels into a pattern that correlates with something in the world: the Declaration of Independence, the opening bars of “Hey Jude,” a cat wearing sunglasses. We say that the signal transmits information about the Declaration or the song or the cat.¹⁰

The information contained in a pattern depends on how coarsely or finely grained our view of the world is. If we cared about the exact sequence of characters in the monkey’s output, or the precise difference between one burst of noise and another, or the particular pattern of pixels in just one of the haphazard displays, then we would have to say that each of the items contains the same amount of information as the others. Indeed, the interesting ones would contain less information, because when you look at one part (like the letter q) you can guess others (such as the following letter, u) without needing the signal. But more commonly we lump together the immense majority of random-looking configurations as equivalently boring, and distinguish them all from the tiny few that correlate with something else. From that vantage point the cat photo contains more information than the confetti of pixels, because it takes a garrulous message to pinpoint a rare orderly configuration out of the vast number of equivalently disorderly ones. To say that the universe is orderly rather than random is to say that it contains information in this sense. Some physicists enshrine information as one of the basic constituents of the universe, together with matter and energy.¹¹

Information is what gets accumulated in a genome in the course of evolution. The sequence of bases in a DNA molecule correlates with the sequence of amino acids in the proteins that make up the organism’s body, and they got that sequence by structuring the organism’s ancestors—reducing their entropy—into the improbable configurations that allowed them to capture energy and grow and reproduce.