Searle begins by stating this fundamental ontology: People live in a world made up entirely of physical particles in fields of force, organized into systems such as planets, mountains, rivers, animals, and humans. Some of these systems are living, and some of these living systems have evolved, through natural selection, nervous systems capable of causing and sustaining consciousness. Consciousness is a physical, biological, and mental feature of humans and certain other animals that can create intentionality. Intentionality is the capacity of the mind to represent, to itself, objects and states of affairs in the world. Many species of animals, especially humans, have a capacity for collective intentionality. This means that they engage in cooperative behavior and, more important, that they share intentional states such as beliefs, desires, and intentions. Searle says that even most forms of human conflict require collective intentionality. Two prizefighters, opposing litigants in a court battle, or two countries at war with each other are all engaging in cooperative collective behavior at a higher level, within which the antagonistic hostile behavior can take place.
One of Searle’s most important and controversial points concerns his distinction between brute facts and institutional facts and the role played by constitutive rules. Brute facts exist independently of any human institutions; they would exist even if humans did not exist. Institutional facts can exist only within human institutions. Constitutive rules are rules that create the very possibility of certain activities. For example, the rules of chess create the very possibility of playing chess. The rules are constitutive of playing chess in the sense that playing chess is constituted in part by acting according to the rules. If one does not play according to at least a large subset of the rules, one is not playing chess. Institutional facts exist only within systems of constitutive rules. Money is an institutional fact because there are certain constitutive rules that govern its existence and use. The fact that the earth is ninety-three million miles from the Sun is a brute fact; it, and all other brute facts, require the institution of language to state the fact, but the distance would remain the same even if there were no humans.