An examination of the role of methodological advice in inference-making. It is argued that the concept of intelligence can best be analyzed in terms of problem-solving behavior, which on the linguistic level is inference-making. The brain is considered as a language machine which contains mechanisms that implement the methodology of inference-making and operates on depressions in "cortical" language, so as to derive conclusions about what to expect and how to respond. An artificial neuron-device is then analyzed, and it is suggested how nets of such devices can be interpreted as mechanisms that form hypotheses, make predictions, and incorporate methods for making and improving inferences. Finally, some ideas are presented on how to formulate an actual theory of artificial intelligence. 43 pp.