Constructs a lucid analysis of the structure of the Tractatus, the terminology used within it and the various interrelationships between its different statements. Stenius concludes that many adherents and critics have misunderstood the main lines of thought. In particular, its basic idea of the "picture theory" of linguistic symbolism remains insufficiently understood and little discussed. Stenius aims to untangle the misunderstandings surrounding the book, often through parallels with Kant.