Extended Theory of Rationality
Chapter 2 presents the main tenets of the extended theory of rationality (ETR). According to ETR, both the given attitudes (“inputs”) and the conclusion of practical reasoning (“outputs”) are actions (more particularly, the intentional pursuit of ends). The principle of instrumental reasoning, which tells us (roughly) to adopt means to our ends, is the only principle of derivation, and a principle (roughly) requiring agents not to pursue incompatible ends is the only principle of coherence. The chapter also presents one of the main theses of ETR; namely that the rationality of an agent through an interval t1-tn does not supervene on the rationality of the agent at each moment t1-tn (what I call the “non-supervenience thesis”). In other words, someone may be irrational over a period of time without there being any moment during that time at which they were irrational.