Practical reasoning and deductive agents
C. L. Walton · Oxford University Press eBooks · 2006
In constructing a reactive agent system, we explicitly define the behaviour of each agent. This behaviour is predefined, and dependent on events in the environment. We now consider a more powerful kind of agent that can make decisions on its own, i.e. an agent with proactive behaviour. Our motivation is the construction of agents with capabilities that are closer to the way that we reason as human beings. Our starting point in this approach is to base the internal processes of the agent directly on current understanding of how human reasoning is performed. This is the principle behind the design of a practical reasoning agent. Practical human reasoning is directed towards actions, that is, figuring out what to do. This is different from purely logical reasoning, which is directed towards beliefs. Human reasoning is believed to consist of two distinct phases: 1. The first phase is deliberation, in which we decide what state of affairs to achieve. 2. The second phase is means–ends reasoning, in which we decide how to achieve the desired state of affairs. To better illustrate human reasoning, it is helpful to consider a small example. Suppose that I wish to find a method of transportation in order to get to work each day. I would typically proceed by considering the various available options and weighing up the pros and cons. For example, I may consider travelling by car, but the available parking may be insufficient. This process of decision-making is deliberation. Once I have fixed upon an appropriate method of transport, e.g. by bicycle, then I must decide how to bring about a situation where this method of transport is possible. This process is means–ends reasoning, and the result is a plan of action. For example, my plan may involve: obtaining the money for the bicycle, finding a shop that sells an appropriate bicycle, and then purchasing the bicycle. If I am able to successfully follow the plan, then I will have reached the intended state of affairs, i.e. I will be able to travel to work by bicycle.