Psychology has a long past, yet its real history is short. For thousands of years it has existed and has been growing older ; but in the earlier part of this period it cannot boast of any continuous progress toward a riper and richer development. In the fourth century before our era that giant thinker, Aristotle, built it up into an edifice comparing very favorably with any other science of that time. But this edifice stood without undergoing any noteworthy changes or extensions, well into the eighteenth or even the nineteenth century. Only in recent times do we find an advance, at first slow but later increasing in rapidity, in the development of psychology.

Psychology is a very unsatisfactory science. Comparing the vast body of systematised and recognised facts in physics with those in psychology one will doubt the advisability of teaching the latter to anybody who does not intend to become a professional psychologist, one might even doubt the advisability of training professional psychologists. But when one considers the potential contribution which psychology can make to our understanding of the universe, one's attitude may be changed. Science becomes easily divorced from life. The mathematician needs an escape from the thin air of his abstractions, beautiful as they are; the physicist wants to revel in sounds that are soft, mellow, and melodious, that seem to reveal mysteries which are hidden under the curtain of waves and atoms and mathematical equations; and even the biologist likes to enjoy the antics of his dog on Sundays unhampered by his weekday conviction that in reality they - are but chains of machine-like reflexes

In its present state of development psychology must be thought of as a young science. There is only one field in which it is relatively well established and in which it has advanced steadily: this is the psychology of sensation and perception. The scientific character of this field is fully recognized. Its findings are based almost entirely on experimental evidence, and even when its theories are in conflict one feels that as far as method is concerned it stands on relatively firm ground. The situation is different with the psychology of will, of needs, and of personality despite the fact that these fields have always attracted popular interest. As recently as fifteen years ago it was assumed that they, by their very nature, were not amenable to scientific methods. The little experimental work that had been done seemed too artificial and abstract to give an insight into the real processes. It was generally accepted that experimental investigations of these elusive and highly complicated processes were intrinsically impossible, at least in so far as human beings are concerned. Thus in Europe these problems were treated in a half-literary, half-philosophical way, and in America the tendency was to study individual differences by means of tests.

Psychology appeared to be a jungle of confusing, conflicting, and arbitrary concepts. These pre-scientific theories doubtless contained insights which still surpass in refinement those depended upon by psychiatrists or psychologists today. But who knows, among the many brilliant ideas offered, which are the true ones? Some will claim that the statements of one theorist are correct, but others will favour the views of another. Then there is no objective way of sorting out the truth except through scientific research.

Our psychology is ... a science of mere phenomena without any metaphysical implications. [It] Treats all metaphysical claims and assertions as mental phenomena, and regards them as statements about the mind and its structure.

Why is psychology the youngest of the empirical sciences? Why have we not long since discovered the unconscious and raised up its treasure-house of eternal images? Simply because we had a religious formula for everything psychic — and one that is far more beautiful and comprehensive than immediate experience. Though the Christian view of the world has paled for many people, the symbolic treasure-rooms of the East are still full of marvels that can nourish for a long time to come the passion for show and new clothes. What is more, these images — be they Christian or Buddhist or what you will — are lovely, mysterious, richly intuitive.

Psychology is the science of mental life

William James defined psychology as the science of mental life, but it could equally be defined as the science of human nature.

Psychology is the science of mental life.” William James

Psychology has most often been defined as science of consciousness, but this definition does not go far enough. For consciousness does not occur impersonally. Consciousness, on the contrary, always is a somebody-being-conscious. There is never perception without a somebody who perceives, and there never is thinking unless some one thinks. And this somebody is not an isolated self but a self which is affected from without and which expresses itself in its behavior. In view of these facts psychology is more exactly defined as science of the self in relation to, or conscious of, its environment.

Psychology is a great science, but – there are no psychologists among us at the moment, I believe. It seems to me we're on uncertain ground.' Fara turned to Hardin. 'Didn't you study psychology under Alurin?' Hardin answered, half in reverie: 'Yes, I never completed my studies, though. I got tired of theory. I wanted to be a psychological engineer, but we lacked the facilities, so I did the next best thing – I went into politics. It's practically the same thing.

Psychology. The Science of Soul, in days of old: a Science which served as the unavoidable basis for physiology. Whereas in our modern day, it is psychology that is being based (by our great scientists) upon physiology.

Psychology is an attempt to gain a scientific understanding of human nature. We are all deeply interested in knowing human nature. When we are not talking about ourselves we are usually talking about our neighbors.

Psychology is the science of psychic states both as to content and form, regarded from an objective standpoint, and brought in relation to the living corporeal individual.