Until recently, it was easy to define our most widely known corporations. Any third-grader could describe their essence. Exxon sells gas; McDonald's makes hamburgers; Walmart is a place to buy stuff. This is no longer so. Today's ascendant monopolies aspire to encompass all of existence. Google derives from googol, a number (1 followed by 100 zeros) that mathematicians use as shorthand for unimaginably large quantities. Larry Page and Sergey Brin founded Google with the mission of organizing all knowledge, but that proved too narrow. They now aim to build driverless cars, manufacture phones and conquer death. Amazon, which once called itself “the everything store,” now produces television shows, owns Whole Foods and powers the cloud. The architect of this firm, Jeff Bezos, even owns this newspaper.