Thus do we hold our destiny in our own hands. If we will cultivate the faculties which are most in need of cultivation, their organs, receiving more blood, will grow faster than any other portions of the brain, while the organs that are kept in check and deprived of activity will gradually decline in power and size, so that the character will become essentially changed. It is in the power of every individual who has the necessary determination to change essentially his own nature for better or worse, as well as to modify and enlarge his capacities, changing the structure of his brain; and this should encourage every young man and woman to make for themselves a noble destiny. Moreover, it is still more practicable to accomplish this by means of education, with all proper appliances for the young; and this should encourage philanthropists to struggle for that social regeneration which is so clearly possible for all the world, as I have shown in "The New Education." The study of the anatomy of the brain and the innumerable experiments I have made on the brain, showing how completely the brain of the impressible can be revolutionized in its action in a few minutes, make it very apparent that society as a whole is responsible for the continued existence of criminals, paupers, and lunatics; for there should not be one, and would not be, if mankind could be aroused from their criminal apathy and ignorance to the performance of our duty in education. But alas! "the light shineth in darkness and the darkness comprehendeth it not." The study of the brain continually leads us into grand philanthropic conceptions by showing the splendid possibilities of humanity,--showing how near we are to a nobler social state from which we are debarred by ignorance, by moral apathy, by ignorant self sufficiency, by intolerant bigotry, and by selfish animality,--qualities which, alas! pervade all ranks to-day. But returning from this digression to our study of the interior of the brain: the great ventricles of which we have considered the position, and which are called lateral ventricles, are interesting for another reason, that they are the central region around which the cerebrum is developed, as it folds over upon itself in its early growth, and consequently must be borne in mind as its centre when we are studying its comparative development in different heads. The basilar organs lie below the ventricles and the coronal organs above. If we have inserted a finger under the corpus callosum, the fibres of which are above our finger, we may feel below, the structure which may be called the bottom of the ventricle, and which is likewise the base or trunk of the superincumbent parts from which they spring, as a tree from its stump.