In Blood Will Tell in Shakespeare's Plays , Dr. Berkeley studies various manifestations of Shakespeare's class bias seen in the poet's division of all human beings in the plays into two genetic classes, gentle and base. Berkeley examines both Renaissance physiology and the Shakespearean applications of it, helping to make this conception seem more credible than superstitious or quixotic. In this light, Shakespeare is seen not as a eugenics propagandist but as one whose characterization of humanity has the solidity of natural process. In the plays, gentles (excepting degenerates) are all endowed, sometimes prodigally, with excellent virtues; and the base born, though sometimes characterized with modestly admirable qualities, usually are portrayed with vices and shortcomings. Thus, Henry V in Shakespeare's plays appears to have mastered many fields of learning without having tutors or being known as a reader of books. His longbowmen, however, who were largely responsible for the British victory at Agincourt, are not given their share of credit because, one may surmise, they did not expose themselves to hand-to-hand combat in the manner of gentlemen (Henry gentles them in consolation only because of some intractable, historical source-stuff). In the Winter's Tale 's primary source, Pandosto, the base shepherd is finally made a knight, a matter evidently so repellent to Shakespeare that he jettisons it. One finds that Shakespeare's plays invariably magnify class distinctions found in the poet's sources. Quality of blood determines what his characters are and how they behave. Thus seen, Shakespeare is firm in the medieval tradition of viewing blood quality in term of hierarchy. The business of his plays is presenting disturbed situations that are finally calmed by the characters' assumption of the places pointed to by the 'kindly enclyning' of their blood. This important conception, which underlies all the Shakespearean plays and sets the poet apart from writers like Chaucer, Marlowe, and Milton, has generally been ignored by critics, many of whom, especially since the Blutezeit of Romanticism, have had an either liberal or Christian bias that does not readily tolerate a blood-based aristocracy and the submerged commonalty that it implies.