In this little book I have endeavoured to maintain the simplicity which is the ideal of this series. It is more difficult, however, to be simple in a topic which, even in its illustrations, demands of the reader more or less facility in the exploration of his own mind. I am persuaded that the attempt to make the matter of psychology more elementary than is here done, would only result in making it untrue and so in defeating its own object.
In preparing the book I have secured the right and welcomed the opportunity to include certain more popular passages from earlier books and articles. It is necessary to say this, for some people are loath to see a man repeat himself. When one has once said a thing, however, about as well as he can say it, there is no good reason that he should be forced into the pretence of saying something different simply to avoid using the same form of words a second time. The question, of course, is as to whether he should not then resign himself to keeping still, and letting others do the further speaking. There is much to be said for such a course. But if one have the right to print more severe and difficult things, and think he really has something to say which would instruct the larger audience, it would seem only fair to allow him to speak in the simpler way also, even though all that he says may not have the merit of escaping the charge of infringing his own copyrights!
I am indebted to the proprietors of the following magazines for the use of such passages: The Popular Science Monthly, The Century Magazine, The Inland Educator; and with them I also wish to thank The Macmillan Company and the owners of Appletons’ Universal Cyclopædia.
As to the scope and contents of the Story, I have aimed to include enough statement of methods and results in each of the great departments of psychological research to give the reader an intelligent idea of what is being done, and to whet his appetite for more detailed information. In the choice of materials I have relied frankly on my own experience and in debatable matters given my own opinions. This gives greater reality to the several topics, besides making it possible, by this general statement, at once to acknowledge it, and also to avoid discussion and citation of authorities in the text. At the same time, in the exposition of general principles I have endeavoured to keep well within the accepted truth and terminology of psychology.
It will be remarked that in several passages the evolution theory is adopted in its application to the mind. While this great theory can not be discussed in these pages, yet I may say that, in my opinion, the evidence in favour of it is about the same, and about as strong, as in biology, where it is now made a presupposition of scientific explanation. So far from being unwelcome, I find it in psychology no less than in biology a great gain, both from the point of view of scientific knowledge and from that of philosophical theory. Every great law that is added to our store adds also to our conviction that the universe is run through with Mind. Even so-called Chance, which used to be the “bogie” behind Natural Selection, has now been found to illustrate — in the law of Probabilities — the absence of Chance. As Professor Pearson has said: “We recognise that our conception of Chance is now utterly different from that of yore…. What we are to understand by a chance distribution is one in accordance with law, and one the nature of which can, for all practical purposes, be closely predicted.” If the universe be pregnant with purpose, as we all wish to believe, why should not this purpose work itself out by an evolution process under law? — and if under law, why not the law of Probabilities? We who have our lives insured provide for our children through our knowledge and use of this law; and our plans for their welfare, in most of the affairs of life, are based upon the recognition of it. Who will deny to the Great Purpose a similar resource in producing the universe and in providing for us all?
I add in a concluding section on Literature some references to various books in English, classified under the headings of the chapters of the text. These works will further enlighten the reader, and, if he persevere, possibly make a psychologist of him.
J. Mark Baldwin.
Princeton, April, 1898.
Psychology is the science of the mind. It aims to find out all about the mind — the whole story — just as the other sciences aim to find out all about the subjects of which they treat — astronomy, of the stars; geology, of the earth; physiology, of the body. And when we wish to trace out the story of the mind, as psychology has done it, we find that there are certain general truths with which we should first acquaint ourselves; truths which the science has been a very long time finding out, but which we can now realize without a great deal of explanation. These general truths, we may say, are preliminary to the story itself; they deal rather with the need of defining, first of all, the subject or topic of which the story is to be told.
1. The first such truth is that the mind is not the possession of man alone. Other creatures have minds. Psychology no longer confines itself, as it formerly did, to the human soul, denying to the animals a place in this highest of all the sciences. It finds itself unable to require any test or evidence of the presence of mind which the animals do not meet, nor does it find any place at which the story of the mind can begin higher up than the very beginnings of life. For as soon as we ask, “How much mind is necessary to start with?” we have to answer, “Any mind at all”; and all the animals are possessed of some of the actions which we associate with mind. Of course, the ascertainment of the truth of this belongs — as the ascertainment of all the truths of nature belongs — to scientific investigation itself. It is the scientific man’s rule not to assume anything except as he finds facts to support the assumption. So we find a great department of psychology devoted to just this question — i.e., of tracing mind in the animals and in the child, and noting the stages of what is called its “evolution” in the ascending scale of animal life, and its “development” in the rapid growth which every child goes through in the nursery. This gives us two chapters of the story of the mind. Together they are called “Genetic Psychology,” having two divisions, “Animal or Comparative Psychology” and “Child Psychology.”
2. Another general truth to note at the outset is this: that we are able to get real knowledge about the mind. This may seem at first sight a useless question to raise, seeing that our minds are, in the thought of many, about the only things we are really sure of. But that sort of sureness is not what science seeks. Every science requires some means of investigation, some method of procedure, which is more exact than the mere say-so of common sense; and which can be used over and again by different investigators and under different conditions. This gives a high degree of verification and control to the results once obtained. The chemist has his acids, and reagents, and blowpipes, etc.; they constitute his instruments, and by using them, under certain constant rules, he keeps to a consistent method. So with the physiologist; he has his microscope, his staining fluids, his means of stimulating the tissues of the body, etc. The physicist also makes much of his lenses, and membranes, and electrical batteries, and X-ray apparatus. In like manner it is necessary that the psychologist should have a recognised way of investigating the mind, which he can lay before anybody saying: “There, you see my results, you can get them for yourself by the same method that I used.”
In fulfilling this requirement the psychologist resorts to two methods of procedure. He is able to investigate the mind in two ways, which are of such general application that anybody of sufficient training to make scientific observations at all can repeat them and so confirm the results. One of these is what is called Introspection. It consists in taking note of one’s own mind, as all sorts of changes are produced in it, such as emotions, memories, associations of events now gone, etc., and describing everything that takes place. Other persons can repeat the observations with their own minds, and see that what the first reports is true. This results in a body of knowledge which is put together and called “Introspective Psychology,” and one chapter of the story should be devoted to that.
Then the other way we have is that of experimenting on some one else’s mind. We can act on our friends and neighbours in various ways, making them feel, think, accept, refuse this and that, and then observe how they act. The differences in their action will show the differences in the feelings, etc., which we have produced. In pursuing this method the psychologist takes a person — called the “subject” or the “re-agent” — into his laboratory, asks him to be willing to follow certain directions carefully, such as holding an electric handle, blowing into a tube, pushing a button, etc., when he feels, sees, or hears certain things; this done with sufficient care, the results are found recorded in certain ways which the psychologist has arranged beforehand. This second way of proceeding gives results which are gathered under the two headings “Experimental” and “Physiological Psychology.” They should also have chapters in our story.