in 1892 i was asked by the harvard corporation to give a few public lectures on psychology to the cambridge teachers. the talks now printed form the substance of that course, which has since then been delivered at various places to various teacher-audiences. i have found by experience that what my hearers seem least to relish is analytical technicality, and what they most care for is concrete practical application. so i have gradually weeded out the former, and left the latter unreduced; and now, that i have at last written out the lectures, they contain a minimum of what is deemed ‘scientific’ in psychology, and are practical and popular in the extreme.

some of my colleagues may possibly shake their heads at this; but in taking my cue from what has seemed to me to be the feeling of the audiences i believe that i am shaping my book so as to satisfy the more genuine public need.

teachers, of course, will miss the minute divisions, subdivisions, and definitions, the lettered and numbered headings, the variations of type, and all the other mechanical artifices on which they are accustomed to prop their minds. but my main desire has been to make them conceive, and, if possible, reproduce sympathetically in their imagination, the mental life of their pupil as the sort of active unity which he himself feels it to be. he doesn’t chop himself into distinct processes and compartments; and it would have frustrated this deeper purpose of my book to make it look, when printed, like a baedeker’s handbook of travel or a text-book of arithmetic. so far as books printed like this book force the fluidity of the facts upon the young teacher’s attention, so far i am sure they tend to do his intellect a service, even though they may leave unsatisfied a craving (not altogether without its legitimate grounds) for more nomenclature, head-lines, and subdivisions.

readers acquainted with my larger books on psychology will meet much familiar phraseology. in the chapters on habit and memory i have even copied several pages verbatim, but i do not know that apology is needed for such plagiarism as this.

the talks to students, which conclude the volume, were written in response to invitations to deliver ‘addresses’ to students at women’s colleges. the first one was to the graduating class of the boston normal school of gymnastics. properly, it continues the series of talks to teachers. the second and the third address belong together, and continue another line of thought.

i wish i were able to make the second, ‘on a certain blindness in human beings,’ more impressive. it is more than the mere piece of sentimentalism which it may seem to some readers. it connects itself with a definite view of the world and of our moral relations to the same. those who have done me the honor of reading my volume of philosophic essays will recognize that i mean the pluralistic or individualistic philosophy. according to that philosophy, the truth is too great for any one actual mind, even though that mind be dubbed ‘the absolute,’ to know the whole of it. the facts and worths of life need many cognizers to take them in. there is no point of view absolutely public and universal. private and uncommunicable perceptions always remain over, and the worst of it is that those who look for them from the outside never know where.

the practical consequence of such a philosophy is the well-known democratic respect for the sacredness of individuality — is, at any rate, the outward tolerance of whatever is not itself intolerant. these phrases are so familiar that they sound now rather dead in our ears. once they had a passionate inner meaning. such a passionate inner meaning they may easily acquire again if the pretension of our nation to inflict its own inner ideals and institutions vi et armis upon orientals should meet with a resistance as obdurate as so far it has been gallant and spirited. religiously and philosophically, our ancient national doctrine of live and let live may prove to have a far deeper meaning than our people now seem to imagine it to possess.

cambridge, mass., march, 1899.