An intuitive approach to the algebra of sets was followed in (THE ALGEBRA OF SETS) in order to make the introduction to Boolean algebra as intuitive and natural as possible. All three of the applications of Boolean algebra mentioned in this book are readily treated in an elementary manner.

However, to discuss each entirely separately, with separate proofs of all important theorems, is a needless waste of time. In addition, such a treatment would tend to emphasize the dissimilarities between the applications rather than their essential unity. For this reason, among others, the present chapter presents a treatment of Boolean algebras in general,  based on a set of definitions and axioms from which all subsequent theorems are derived. There will be . ome duplication of the material introduced in  (THE ALGEBRA OF SETS), of course, but whereas the results of (THE ALGEBRA OF SETS) were based on intuitive concepts and applied only to sets, results in this chapter are derived in a rigorous manner, and apply equally well in every Boolean algebra.