Universal Acid

is how Daniel Dennett in Darwin's Dangerous Idea describes the effect of Darwin's theory of natural selection in almost every area of modern intellectual inquiry. Dennett sees Darwin as providing a revolutionary explanation of how the complexity of life can exist without positing a cosmic intelligence directing its development. In a running comparison with Turing and Von Neumann's discoveries in the area of artificial intelligence, Dennett describes evolution as an "algorithmic" process that operates much the way computer programming does: simple instructions can produce complex results.

Dennett defines an algorithm as having the following characteristics:

(1) substrate neutrality: The procedure for long devision works equally well with pencil or pen, paper or parchment, neon lights or skywriting, using any symbol system you like. The power of the procedure is due to its logical structure, not the causal powers of the materials used in the instantiation just so long as those causal powers permit the prescribed steps to be followed exactly.

(2) underlying mindlessness: Although the overall design of the procedure may be brilliant, or yield brilliant results, each constituent step, as well as the transition between steps, is utterly simple. How simple? Simple enough for a dutiful idiot to perform — or for a straightforward mechanical device to perform. The standard textbook analogy notes that algorithms are recipes of sorts, designed to be followed by novice cooks. A recipe book written for great chefs might include the phrase "Poach the fish in a suitable wine until almost done," but an algorithm for the same process might begin, "Choose a white wine that says 'dry' on the label; take a corkscrew and open the bottle; pour an inch of wine in the bottom of a pan; turn the burner under the pan on high; . . . " — a tedious breakdown of the process into dead simple steps, requiring no wise decisions or delicate judgments or intuitions on the part of the recipe-reader.

(3) guaranteed results: Whatever an algorithm does, it always does it, if it is executed without misstep. An algorithm is a foolproof recipe.

The mindless process of natural selection, by which selective pressures winnow out species from amongst the rich diversity of random mutation, is just such an algorithm — or group of algoriths — Dennett argues. As such, given millions of years to operate, it is perfectly capable of explaining the complexity of modern life, the existence of humanity, and the development of consciousness.

Such an explanation based on randomness and mindless algorithms dissolves in its elegant simplicity many traditional explanations of humanity's place in the universe, engendering quite a bit of hostility, hence the moniker universal acid.