Common sense: An investigation in ontology, epistemology, and moral philosophy

We shall identify the subset of objective reality that all people experience during their everyday lives as the common-sense world. The most prominent occupants of this world are medium-sized physical things and people. However, the common-sense world is a rich and exciting domain that is also home to countless other kinds of entities.;Common sense, then, is the sophisticated, true, and reliable set of fundamental beliefs and abilities shared by all human adults. This knowledge base underlies whatever other knowledge we might obtain, and it allows us to provide expert explanations and predictions about the common-sense world. Like knowledge in general, common-sense knowledge may be either declarative ("knowing that") or procedural ("knowing how"). Since common sense includes both procedural and declarative knowledge, its justification is both intuitive and pragmatic. Young children acquire common sense through simple experience with the common-sense world, not by undertaking any formal instruction or systematic inquiry.;Among common sense's most general claims is common-sense realism , a commitment to the objective existence of the common-sense world. The more specific theory of common-sense psychology explains the behavior and mental activity of people in terms of their beliefs and desires. Likewise, naive physics attempts to describe, explain, and predict the behavior of the purely physical parts of the common-sense world.;Just as there are common-sense theories of psychology and physics, there is also a commonsensical theory of ethics. This important component of common sense is a prerequisite for more sophisticated moral philosophy. It is also a crucial component of common-sense psychology, since we presuppose it during our everyday interactions with others.