Even accepting the solution (if such it maybe called) of the two first difficulties--life added spontaneously or aboriginally to matter, and thought and consciousness added to organism--still the rest of the path is by no means so easy as might at the first glance appear. Development in brain structure certainly does not always proceed _pari passu_ with a higher and more complex reasoning. In actual fact we find high "reasoning" power, quite unexpectedly here and there, up and down the animal kingdom. Some _insects_, with very little that can be called a brain at all, exhibit high intelligence; and some animals with smaller brains are more docile and intelligent than others with a much larger development. The ape, in spite of his close physical approach to the structure of man, and his still greater relative distance from the other animal creation, is not superior (if he is not decidedly inferior) in reason or intelligence to several animals lower down in the scale. Savages, again, have a brain greatly in excess of their actual requirements (so to speak). Hence the mere existence of brain, however complex, does not indicate the possession of mental power. There is reason to believe that all thought and exercise of the mind--in fact, every step in the process of "Education," whereby an ignorant person is brought at last to apprehend the most abstract propositions--is accompanied by some molecular (or other) change. So that a person who has been carefully educated has the brain in a different state from that of an exactly similarly constituted person whose brain has been subjected to no such exercise. But even if this action could be formulated and explained, it would not follow that thought is the _product_ of the molecular change; or that, _vice versâ_, if we could artificially produce certain changes, in the brain, certain thoughts and perceptions would thereon coexist with the changes, and arise in the mind of the subject forthwith. And if not, then no process of physical development accounts for grades of intellect; we have only mind developing as mind. But the theory of evolution will have nothing to do with any development but physical; or at any rate with mental development except as the result of physical: it knows nothing of pure mind, or spiritual existence, or anything of the sort.