Book digitized by Google from the library of Oxford University and uploaded to the Internet Archive by user tpb.
v. 1. Book I. Formal logic, deductive and inductive. Book II. Number, variety, and probability. Book III. Methods of measurement. -- v. 2. Book IV. Inductive investigation. Book V. Generalization, analogy, and classification. Book VI. Reflections on the results and limits of scientific method