“New historicism,” as those very words suggest, is thought of as a response and even alternative to earlier kinds of historical criticism. According to many “new historicists,” traditional historical criticism tended to present too simple a view of the relationships between literature and history.
One book that was frequently (and perhaps unfairly) attacked by early new historicists was E. M. W. Tillyard’s small overview titled The Elizabethan World Picture. As Ty Buckman notes in the article linked below,
Tillyard’s book promises to identify and catalogue the underlying structure of the Elizabethan worldview, as his preface states: ‘The province of this book is some of the notions about the world and man which were quite taken for granted by the ordinary educated Elizabethan; the utter commonplaces too familiar for the poets to make detailed use of except in explicitly didactic passages’ (Tillyard 1941: vii).
Practically every word of Tillyard’s title is vulnerable to objections from new historicists. Thus, the word “The” can imply that there was only one way in which “Elizabethans” viewed the world. The title would have entirely different implications if it were Elizabethan World Pictures or Competing Elizabethan Views of the World. However, the word “Elizabethan” is also objectionable from a new historicist point of view. That word tends to focus our attention on Queen Elizabeth I and other members of the powerful aristocracy. It neglects to imply any attention to those lower on the spectrums of political, social, and economic power, especially the poor and/or other “marginalized” groups, such as Jews, blacks, and (ironically) even women (“ironically” since Elizabeth herself was, of course, a woman). New historicism tries to focus much more attention on these marginalized groups. New historicists assume that the more we know about previously neglected groups, texts, contexts, and other kinds of previously overlooked evidence, the more complex picture we will have of any given culture and of the literature that emerged from that culture.
Finally, the term “World Picture,” besides being extremely monolithic, also implies that it is a “world picture” that influences literature rather than the more messy, more complicated idea that literature and its “contexts” interact, each influencing the other in a constant process of negotiation (a key term for new historicists). New historicists also tend to be concerned with “power” and “power relations,” because they assume that all aspects of a culture, down to its tiniest details, involve struggles for power.
Thus, the key difference between “new historicism” and “traditional historical criticism” is the claim that the former is far more complex and complicating than the latter.