The reader who desires to study further on the sub-ject of thinking will find a wide field before him—but he will have to search in cos-mo-pol-i-tan quarters. While much has been written on thinking, it has been in an incidental manner, and has found its way into books written mainly to il-lum-i-nate other subjects. Among the few books or essays devoted exclusively or mainly to thinking may be mentioned:—John Locke, The Conduct of the Under-stand-ing; Isaac Watts, The Improvement of the Mind; Arnold Bennett, Mental Efficiency; T. Sharper Knowlson, The Art of Thinking; Arthur Schopenhauer, On Thinking for Oneself, in his Essays. The last is especially recommended. It is only about a dozen pages long, and is the most stimulating essay written on the subject. This, together with John Locke’s Conduct (which, by the way, is also fairly short) may be con-si-dered the two “classics” in the meager literature on thinking.

There is an extensive literature on the psychology of reasoning, on the “positive” science of thinking. The best single work on this subject is John Dewey’s How We Think. William James’ chapter on Reasoning in his Principles of Psychology might also be consulted with profit. S. S. Colvin’s, The Learning Process con-tains some in-teresting chap-ters bearing on thought.

On method, the amount of literature is even more imposing than that on the psychology of reasoning. Probably the most thorough book is Stanley Jevon’s The Principles of Science, though this, consisting of two volumes, will require quite some ambition to attack. A good recent short work is J. A. Thomson, Introduction to Science. Herbert Spencer’s short essay, An Element in Method, in his Various Fragments might also be mentioned. Of those works treating method mainly from a corrective standpoint, I have already mentioned Jevon’s Elementary Lessons in Logic. The authoritative and most comprehensive book............