Stop the world—I want to think

✍ Scribed by Donald Perlis; Jennifer J. Elgot-Drapkin; Michael Miller

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 862 KB
• Volume: 6
• Category: Article
• ISSN: 0884-8173
• DOI: 10.1002/int.4550060406

✦ Synopsis

Reason-based actions plunge the reasoner into temporal considerations from all angles. We see this not only when time enters explicitly into the problem statement, but also in formal robot blocks-world scenarios, in the Yale Shooting Problem, and other associated versions of the frame problem (e.g., Hanks and McDermott'), in various specialized actions (e.g., hiding, as in Allen2), and so on. In short, where there is action, there is time, and where there is time, there is a potential need for reasoning about time. Where, then, is the action? It certainly includes the usual overt physical acts of motion, and also certain covert behaviors such as hiding or watching. In these, of course, time is important. But there is another angle that is not usually noted, one that we have been exploring for the past several year^.^-^ Namely, action also occurs in the form of mere thinking or reasoning. Moreover, the very same temporal considerations apply to this reasoning behavior. This leads us to view reasoning itself as a kind of action, with the obvious yet nontrivial consequence that our reasoning goes on "as the world turns." The present article offers various arguments in support of this position.

I. INTRODUCTION

Actions in A1 are traditionally viewed as separate from the planning process that leads t o those actions. Even when the two are intertwined, as in real-time, dynamic, or reactive planning, still the planning effort is usually treated as a *With apologies to Leslie Bricusse and Anthony Newley. tSupported in part by ARO research contract No. DAAL03-88-K0087.