Transactions in cyberspace, like those that take place in more traditional settings, are not always conducted directly by the principals. Sometimes it's a case of "My assistant will call your assistant": the task is delegated to agents. Use of agents frees your time for other things, which becomes particularly important when the transactions that you must conduct are numerous and time-consuming.
As online activity has grown, so has the realization that the denizens of cyberspace, like the Greek citizens contemplated in Aristotle's Politics, will need the help of reliable agents to do their bidding. Aristotle, notoriously, described the kind of agents that he had in mind-human slaves-as "live tools" needed to support the "good life." He elaborated: "Tools may be animate as well as inanimate; for instance, a ship's captain uses a lifeless rudder, but a living man for watch; for a servant is, from the point of view of his craft, categorized as one of its tools. So any piece of property can be regarded as a tool enabling a man to live, and his property is an assemblage of such tools; a slave is a sort of living piece of property." Then he went on to imagine, as an aside, a species of artificially intelligent tools that would bail him out of the mess that this morally obtuse line of reasoning had landed him in: "For suppose that every tool we had could perform its task, either at our bidding or itself perceiving the need, and if-like the statues made by Daedalus or the tripods of Hephaestus ...-shuttles in a loom could fly to and fro and a plucker play a lyre of their own accord, then master craftsmen would have no need of servants nor masters of slaves." 14
Such automata were not available in ancient Greece, but in cyberspace they are; programmers can construct intelligent bit puppetssoftware tools to do their bidding. The idea of autonomous software agents that can not only perform useful tasks, but also-at least to some extent-learn from experience and make certain decisions on their own goes back to some investigations in the 1960s by the artificial intelligence pioneer Oliver Selfridge. 15 In the 1980s Marvin Minsky's book The Society of Mind provided inspiration and some important technical underpinnings. 16
By the 1990s the vast scale of the online world and the huge bit glut that it provided had made agents seem a necessity. They began to show up in some MUDs, where software objects known as bots may interact with human players to serve as guides, to hawk real estate, and sometimes even to sucker the unwary into TinySex. Serious users of online information began to rely on search agents that know where to find certain sorts of material, can go out on the network and get it for you, and can perhaps even present it in convenient and attractive formats of your own choosing. 17 Desperate users of e-mail began to employ agents that would filter out junk mail and prioritize the rest. Newsgroup junkies turned with relief to the Stanford Netnews Filter, which reads all 10,000-plus newsgroups on the Usenet message network each day and e-mails back the ones containing specified key phrases. Engineers created agents to control electricity networks, and astronomers used agents to schedule telescope time. 18 Personal computers began to lodge agents that would watch users transacting their daily business of answering correspondence and scheduling meetings, look for patterns, and automate these where appropriate. 19 And as more and more business is transacted in cyberspace, it seem inevitable that we will see increasing use of agents that automatically seek out offers of goods and services, negotiate prices, and make purchases. Let your agents do the walking!
Early in 1994 the general public began to hear a lot more about the hitherto esoteric topic of agents when General Magic-a much watched and talked-about Silicon Valley startup-rolled out its Telescript and Magic Cap software. Telescript is a specialized programming language for conveniently creating agents and virtual places. Magic Cap is an entry point to this world of agents and places-a graphic operating system that presents cyberspace as a cute, Disneyland-like "Main Street" filled with "shops" maintained by organizations that want to hawk their wares and services. You can go shopping yourself, by entering programmed places and interacting with the agents that you find there. Or you can delegate the task by sending your agents out to meet other agents.
As software agents have appeared on the scene, more and more cyberspace places have acquired attendants that guide you through whatever is available there and help you to make use of it-much as shops have shop assistants, offices have receptionists, hotels have concierges, and libraries have librarians. In MUDs-in a new twist on the Turing test-visitors sometimes find it difficult to tell whether they are interacting online with fellow humans or with clever pieces of software.
It isn't hard to imagine the social and urban problems that could emerge as agent populations grow. 20 Computer viruses and worms are maliciously constructed agents-fanning out, like Fagin's boys, to cause trouble. Will there will be a criminal underclass? Will faulty programming produce destructive, uncontrollable rogue agents? Since agents are easy to reproduce, cyberspace may be flooded with billions of them; how will population be controlled? How will the law deal with agents that perform important tasks on behalf of distant, perhaps oblivious originators? 21 Even if our agents turn out to be very smart, and always perform impeccably, will we ever fully trust them? And how will we deal with the old paradox of the slave? We will want our agents to be as smart as possible in order to do our bidding most effectively, but the more intelligent they are, the more we will have to worry about losing control and the agents taking over.
So history replays itself. The great cities of the past required large labor forces to run them; they imported slaves or attracted immigrants seeking work. So Greek and Roman houses had slave quarters, slums grew up in the shadows of factories in nineteenth-century industrial cities, and modernist architects of the early twentieth century became preoccupied with providing inexpensive, high-density (often high-rise), repetitive worker housing. And the burgeoning, increasingly indispensable, programmed proletariats of cyberspace cities now live invisibly on disk drives.