Shakespeare's Theories of Blood, Character, and Class is a collection of essays that explores the works of Shakespeare by applying David Shelley Berkeley's approach to them as literary manifestations of Elizabethan political, scientific, and social thought. Elizabethan scientific and medical principles held that, from conception, human beings were endowed with either hot or cold blood; as a result, the moral nature of individual human beings was considered as much a matter of physiology and eugenics (nature) as of moral instruction (nurture). With the best blood preserved among the aristocracy by selective breeding and by the consumption of the best food and drink and with the worst blood sustained among the lower classes by base parentage and by the enforced consumption of inferior sustenance, the Elizabethan citizenry - like Shakespeare's characters - found itself rigidly stratified into social classes reflective of the widely varying quality of its blood. Shakespeare's Theories of Blood, Character, and Class enhances the many current readings of Shakespeare on the basis of humors psychology by illuminating a neglected component of Elizabethan thought that is essential to a full understanding of Shakespeare and his times.