It's probably somewhat quicker to run a WebCrawler search on "Aristotle" and "Rhetoric," a screen search on "topoi" and print a screen shot from a home or office interface than it is to go to the library, find the book, use the index and stand in line for the copier. But only somewhat ... and only probably.  The matters of connection lag and download time are only two that might tip the convenience scales in favor of the papertextual search. But this is not necessarily the kind of timeliness that a website is best at promoting.