Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: I. THE DIFFERENTIAE OF CONSCIOUS AND UNCONSCIOUS MENTAL ACTIVITY AND THE UNITY OF WILL AND IDEA IN THE UNCONSCIOUS. 1. The, Unconscious docs not fall ill, but conscious mental activity can sicken if its material organs suffer disturbances, whether from bodily causes, or through violent shocks, arising from violent mental emotions. This point, so far as we are able to enter upon it, has been already touched upon in the chapter on the Vis Mediatrix (vol i. 161-168). 2. The Unconscious does not grow weary, but all conscious mental activity becomes fatigued, because its material organs become temporarily unserviceable, in consequence of a quicker consumption of material than nutrition can repair in the same time. Undoubtedly, fatigue may be avoided by occupying a different sense, or by changing the object of thought or of sense-perception, because then other organs and parts of the brain are brought into requisition, or at least the same organs are constrained to a different kind of activity; but the general fatigue of the central organ of consciousness is not to be prevented, even by the change of objects, and with every new object takes place the sooner, the longer attention has already been absorbed with other objects, until at last complete exhaustion ensues, which is only to be compensated by fresh absorption of oxygen during sleep. The more we approach the sphere' of the Unconscious the less is fatigue observable, as, for example, in the department of the feelings, and the less defined they are inconsciousness, for so much the more does their proper essence belong to the Unconscious. Whilst a thought is probably not to be retained in consciousness without interruption for more than two seconds, and thinking grows weary in a few hours, one and the same feeling remains, w...