Do not fail to read this book if you love Shakespeare and want some understanding of what his work as a whole is about. Let me carefully explain why.
Girard has a few devoted followers and very few adversaries. His bold interpretation of western literature (lets put aside his entire mimetic theory for a moment) is so far away from everything else in literary theory that other scholars find it very difficult to elaborate a refutation - they would have to re-examine too much that is taken for granted and that is the basis for all literary criticism, old and contemporary. So most of the disagreement with Girard is short and dismissive, rather than a careful critique.
This is indeed a very regrettable situation. Girard`s study is too decisive to be treated as a footnote, and too persuasive to be dismissed. If he is correct, than he found the key to interpret all great western literature. We know that Shakespeare, Dostoyevsky and Cervantes, not to mention the Greek tragedians, are somehow set apart from other writers in that they provide a superior portrait of human condition, but little has been done to explain why. Why are Don Quixote and Hamlet so outstanding? I think only Girard elaborated an answer. And it is a very disturbing one. Scholars and non-scholars have a natural reaction to dislike the idea that the characters in great literature are so universal because they show how non-autonomous people are, rather than the opposite.
But one must take Girard`s ideas seriously. In the case of this book, how can one dismiss the mountain of evidence Girard presents to prove that Shakespearean characters are slaves to other people's desires? How can one read this book and not treat this hypothesis seriously? Because if you do, and if you end up agreeing with it, you may feel like a fool - all the literary critics you ever read, and their respective schools of thought, and the institutions to which they belong - become almost redundant and peripheral, and this relatively little-known dude from Stanford acquires an immense importance. Even the individual reader feels like silly because he missed something so ubiquitous. So in a way, Girard`s mimetic theory explains Rene Girard's relative obscurity.
So there is greater benefit in reading Theater of Envy if you are NOT an English major, and have read a lot more Shakespeare than commentary about Shakespeare. You will have a lot less prejudice, and you will be flabbergasted by Girard demonstrating over and over again what that body of work is about.
One other thing of interest is: if you are already acquainted with the mimetic theory (and I strongly recommend you read Deceit, Desire and the Novel before tackling this one), you already know a lot of what the author is going to say (assuming you are acquainted with the Bard`s plays). For example, much of what the Chapter on Hamlet contains I already knew would be there, just by applying Girard`s theory to a play I knew well. And I could probably write myself a couple of extra chapters to this book, tackling Henry VI parts II and III, two very "mimetic" plays Girard left out for some reason. Actually, it is interesting that there is only one chapter on Hamlet, a play that corroborates so much of Girard`s theory, and two on As You Like It, a play where the mimetic desire appears little. Girard wants to go for the difficult stuff, the elements in Shakespeare that apparently contradict him, so that we will be all the more persuaded. Why insist on Hamlet and Othello if the reader will easily be convinced himself?
One last reason to read this book. Girard is a great writer, period. His prose and his clear presentation make it a delightful read. The only obstacle to reading this book is complete unfamiliarity with Shakespeare - I skipped the chapter`s on Winter`s Tale because I know nothing about that play other than the title. Other than that, reading Deceit Desire and the Novel first is a very good idea, but not indispensable if you are a Shakespeare buff. I suspect you will probably jump to reading more Girard afterwards anyways.