8. So far I have spoken of local dissolution occurring on but one-half of the nervous system on different levels. Coming to the highest centers I speak of uniform dissolutions—of cases in which all divisions of these centers are subjected to the same evil influence. I choose some cases of insanity. In doing this I am taking up the most difficult of all nervous diseases. I grant that it is not possible to show in detail that they exemplify the principle of dissolution, but choosing the simplest of these most complex cases we may show clearly that they illustrate it in general. I take a very commonplace example—delirium in acute non-cerebral disease. This, scientifically regarded, is a case of insanity. In this, as in all other cases of insanity, it is imperative to take equally into account not only the dissolution but the lower level of evolution that remains. The patient's condition is partly negative and partly positive. Negatively, he ceases to know that he is in hospital, and ceases to recognize persons about him. In other words, he is lost to his surroundings, or, in equivalent terms, he is defectively conscious. We must not say that he does not know where he is because he is defectively conscious; his not knowing where he is, is itself defect of consciousness. The negative mental state signifies, on the physical side, exhaustion, or loss of function, somehow caused, of some highest nervous arrangements of his highest centers. We may conveniently say that it shows loss of function of the topmost layer of his highest centers. No one, of course, believes that the highest centers, or any other centers, are in layers; but the supposition will simplify exposition. The other half of his condition is positive. Besides his not knowings, there are his wrong knowings. He imagines himself to be at home or at work, and acts as far as practicable as if he were; ceasing to recognize his nurse as a nurse, he takes her to be his wife. This, the positive part of his condition, shows activity of the second layer of his highest centers; but which, now that the normal topmost layer is out of function, is the then highest layer; his delirium is the "survival of the fittest states," on his then highest evolutionary level. Plainly, he is reduced to a more automatic condition. Being (negatively) lost, from loss of function of the highest, latest developed, and least organized, to his present "real" surroundings, he (positively) talks and acts as if adjusted to some former "ideal" surroundings, necessarily the more organized.
I now make some general remarks on the eight illustrations, in order to prevent certain misunderstanding. It is asserted, again, that each of the eight cases is a different dissolution. All that is meant is that each shows a reduction from the voluntary toward the automatic in what the center, or part of it, which is diseased, represents. If we take extreme cases, the case of progressive muscular atrophy and the case of insanity (delirium in acute non-cerebral disease), we say that the two are alike, because in each there is reduction to a more automatic condition, and we say, too, that they are very unlike, the
