It is not the purpose of this book to trace the origin of his ideas or their influence on contemporary discussion. But any reader who will glance at Professor Perry's annotated "List" of his published work may see that he had written important papers by 1883, and that most of what was original in his psychology must by then have been present to his mind. During the visit he had just made to Europe, he had got a personal impression of the transatlantic colleagues whose writings had interested him especially, and had spent many hours in the company of certain among them with whom he found himself to be particularly in sympathy. Thus he had gained a bracing sense of comradeship with the men who were collaborating in his field. Last of all, he had brought home with him a happy conviction that the most propitious place for him to teach and write his book in was the philosophical department of his own University. So far as the "textbook on Psychology" was concerned, however, he still underestimated the amount of original investigation and thought which his instinct for "concrete" reality was to exact of him. Perhaps also he made too little allowance for the inadequacies of current laboratory methods and of the existing literature of the subject. Helmholtz and Wundt had already published important reports from their laboratories in Germany; but psychology was still generally considered to be an inductive science, which achieved its purposes by introspection and description, and which had no very broad connection with physiology nor many laboratory methods of its own. James had still to help make a modern science of it by his own immense effort. He may perhaps be said to have set to work when he offered the course on "The Relation between Physiology and Psychology" to graduate students in 1875, and made the class take part in experiments which he arranged in a room in the Lawrence Scientific School building.[68] Thus with teaching, experimenting, and occasionally writing out his conclusions as he went along, he ploughed his way through his subject. The triple process is familiar enough today to most men of science. But James and the majority of his contemporaries had been trained differently or not at all; and their generation, following a few great leaders like Pasteur, Darwin and Helmholtz, had to establish new standards of criticism and new methods of inquiry in every department of science. When the "Psychology" was drawing to its completion, James wrote two sentences about his difficulties to his brother Henry. They might equally well have been written at any other time during the eighties. "I have," he said, "to forge every sentence in the teeth of irreducible and stubborn facts. It is like walking through the densest brush-wood." * * * * * There was one peculiarly stubborn and irreducible class of facts which he took up and gave much thought to during this period.