by slow gradations, and the special interpretations of reflex action, instinct, memory, reason, emotion, and will are such as to make the Principles of Psychology indubitably the most suggestive book upon mental phenomena that was ever written.
Toward the end of the first edition of The Origin of Species, published in 1859, Mr. Darwin looked forward to a distant future when the conception of gradual development might be applied to the phenomena of intelligence. But the first edition of the Principles of Psychology, in which this was so successfully done, had already been published four years before—in 1855—so that Mr. Darwin in later editions was obliged to modify his statement and confess that, instead of looking so far forward, he had better have looked about him. I remember hearing Mr. Darwin laugh merrily over this at his own expense.
This extension of the doctrine of evolution to psychical phenomena was what made it a universal doctrine, an account of the way in which the world, as we know it, has come to be. There is no subject great or small that has not come to be affected by the doctrine, and, whether men realize it or not, there is no nook or corner in speculative science where they can get away from the sweep of Mr. Spencer's thought.
This extension of the doctrine to psychical phenomena is by many people misunderstood. The Principles of Psychology is a marvel of straightforward and lucid statement; but, from its immense reach and from the abstruseness of the subject, it is not easy reading. It requires a sustained attention such as few people can command except on subjects with which they are already familiar. Hence few people read it in comparison with the number who have somehow got it into their heads that Mr. Spencer tries to explain mind as evolved out of matter, and is therefore a materialist. How many worthy critics have been heard to object to the doctrine of evolution that you can not deduce mind from the primeval nebula unless the germs of mind were present already! But that is just what Mr. Spencer says himself. I have heard him say it more than once, and his books contain many passages of equivalent import.[1] He never misses an opportunity for attacking the doctrine that mind can be explained as evolved from matter. But, in spite of this, a great many people suppose that the gradual evolution of mind must mean its evolution out of matter, and are deaf to arguments of which they do not perceive the bearing. Hence Mr. Spencer is so commonly accredited with the doctrine which he so earnestly repudiates.
But there is another reason why people are apt to suppose
- ↑ See, for example, Principles of Psychology, vol. ii, pp. 145-162.
