What is a computer? Steve Jobs famously described the computer as “a bicycle for the mind” — a tool to help us remember, think, discover, and create. Computers are high-tech, universal tools; they’re so useful, in fact, that some of us spend all day in contact with some sort of digital device.
There’s another way, though, to think about what a computer is: not as a high-tech tool, but as a profound intellectual achievement. In a deep sense, the power of the computer is as much about ideas as it is about circuits. The incredible, open-ended flexibility that makes computers so powerful — and that lets us use them to figure out everything from climate modeling to “Jeopardy!” — is, in fact, the product of more than two thousand years of painstaking, hard-won intellectual progress in low-tech fields like mathematics, logic, and philosophy. Like the tide line on a beach, the computer marks the furthest we’ve progressed in a philosophical quest to understand, perfect, and extend the reach of reason.