ABSTRACT
A society consists of individual members and a society’s decision is composed of its members’ decisions. Each society has its own rule for making decisions. When a combination of individual decisions is given, a society’s decision is reached according to that rule. Probably the most familiar example of a social decision-making rule is voting. By casting a ballot, each individual expresses his decision on the issue in question, say, an election where a Conservative candidate and a Labour candidate are contesting a seat in Parliament. Society adopts the decision supported by the majority of voters; thus, if the Conservative candidate obtains more votes, he is the ‘social choice’. Once a pattern of individual decisions is formed, the rule of majority voting yields a social decision. As the pattern changes, the social decision also varies. The mathematician, as well as the logician, would say that a social decision is a function of individual decisions, in the sense that a combination of individual decisions determines a social decision. More formally, we may express this as https://www.w3.org/1998/Math/MathML"> R = F ( R 1 , R 2 , … R n ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315763538/3777e668-d6f7-4331-b3ce-08969dd0189a/content/math_1_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>
