A closer examination of reflex action requires consideration of certain properties, which in themselves cannot easily have criminal significance, but which tend to make that significance clearer. One is the circumstance that there are reflexes which work while you sleep. That we do not excrete during sleep depends on the fact that the faeces pressing in the large intestine generates a reflexive action of the constrictors of the rectum. They can be brought to relax only through especially powerful pressure or through the voluntary relaxation of one’s own constrictors.
The second suggestive circumstance is the fact that even habitual reflexes may under certain conditions, especially when a particularly weighty different impression comes at the same time, not take place. It is a reflex, for example, to withdraw the hand when it feels pain, in spite of the fact that one is so absorbed with another matter as to be unaware of the whole process; but if interest in this other matter is so sufficiently fixed as to make one forget, as the saying goes, the whole outer world, the outer impression of pain must have been very intense in order to awaken its proper reflex. The attention may, however, not be disturbed at all and yet the reflex may fail. If we suppose that a reflex action is one brought about through the excitement of an afferent sensory nerve which receives the stimulation and brings it to the center from which the excitement is transferred to the motor series (Landois[106]), we exclude the activity of the brain. But this exclusion deals only with conscious activity and the direct transition through the reflex center can happen successfully only because the brain has been consciously at work innumerable times, so that it is coöperating in the later cases also without our knowing it. When, however, the brain is brought into play through some other particularly intense stimuli, it is unable to contribute that unconscious cöoperation and hence the reflex action is not performed. On this point I have, I believe, an instructive and evidential example. One of my maids opened a match-box pasted with paper at the corner by tearing the paper along the length of the box with her thumb-nail. Apparently the box was over-filled or the action was too rapidly made, for the matches flamed up explosively and the whole box was set on fire. What was notable was the fact that the girl threw the box away neither consciously nor instinctively; she shrieked with fright and kept the box in her hand. At her cry my son rushed in from another room, and only after he had shouted as loudly as possible, “Throw it away, drop it,” did she do so. She had kept the burning thing in her hand long enough to permit my son to pass from one room into another, and her wound was so serious that it needed medical treatment for weeks. When asked why she kept the burning box in her hand in spite of really very terrible pain she simply declared that “she didn’t think of it,” though she added that when she was told to throw the thing away it just occurred to her that that would be the wisest of all things to do. What happened then was obviously this: fear and pain so completely absorbed the activity of the brain that it was not only impossible for it consciously to do the right thing, it was even unable to assist in the unconscious execution of the reflex.