4.5 stars. This giant of a book should be a model for all biographies in terms of the sheer research and the resulting details about not only the life but also the thoughts and works of its subject, Ludwig Wittgenstein. It does get a little tiring at times and given that the subject matter of Wittgenstein’s work was so abstract, things are many times difficult to fully understand but the book does a well enough job of rounding up his life and work into a coherent narrative so that we can actually feel Wittgenstein transitioning from one phase or mode of thinking to another while simultaneously keeping an eye on the status of his real world dealings.