the individual the courage for risky undertakings. Certain drugs which influence mental disturbances are particularly interesting from the medical point of view. The effect of stronger doses of ethyl alcohol is revealing; such doses lead to a dimming of consciousness, even to total loss of con- sciousness. This observation indicates an important sensitivity of consciousness to chemical influences (J7), which is further revealed in the action of anesthetics upon basic properties of cerebral elements. Such modifications show that chemically defined receptors, as constituents of nerve cells, are in play at the molecular level. Little is known aboutthis field today; however, Thus the actions of LSD may be considered a modification of discharge of nervous elements of the visual system. As mentioned above, fragments of stored experience are often part of the activated pattern of excitation. An example is one subject’s identification of a wall with a railway embankment. A hallucination was joined to this ilfusion; the subject believed that he saw an overhead electric line, which in re- ality was not there but which belonged to the full picture of the electrified Swiss train system. From this, it. appears that the mechanism of hallucination may eventually become understood through a biologically oriented approach. Causality and Motivation of Behavior the means for further investigation are at hand—for example, through study of the effect of drugs on explants of clinical biopsy material. In addition to drugs which suppress consciousness there are drugs whose action manifests itself in the psychic sphere in other ways. One of these, The behavior of a cat in an open field on the lookout for an enemy seems: to be motivated by the imminent threat. The cat’s watchfulness and active search for a refuge confirm this interpretation. While emotions may be the impelling force, the waking consciousness determines the organization of a lysergic flight reaction. For successful avoidance, acid diethylamide (LSD), is an appropriate “research instrument.” Even minimum doses produce very striking psychic effects—for example, primitive visual perceptions such as colored clouds and changes in brightness of visual patterns, like scintillations or flickerings. One psychiatrist (78) has described more complex visu- coordinated muscular action is called upon. Such action occurs through excitation of precisely defined central mechanisms. To meit is clear that such an explanation can be deduced only from one’s own experience. From the objective point of view one might take exception to this interpretation. On the ments, fern branchings, and wood carv- expected to be guided in their view by their specialized knowledge concerning the organization of brain and behavior—knowledge which has led to the recognition of principles applicable in both man and other higher animals. Such is the problem of motive and execution of acts controlled by the con- al impressions, such as spirals, orna- ings, which he experienced in a selftrial. Such imagery arises from latent memory traces. Even more impressive is the case where fragments of ac- quired knowledge appear in the visual field—for instance, images of benzene rings or chromosomes. Experiences of this nature are noteworthy because similar visual phenomena, such as stars, wheels, colored balls, and disks, are reported by the patient when the brain surgeon applies electrical current to the occipital cortex for purposes of diagnosis (4). Artificially elicited perception of the contents of consciousness, on the one hand through electrical stimulation and on the other hand through the administration of a chemically defined substance, is all the more arresting because this activity is based on excitation of elements that lie in the visual-projection areas of the brain. 1282 other hand, scientific observers can be scious will. Therefore, the question is, Where do the activating impulses originate? One may say that this category of phenomena cannot be compared with the category discussed above. On the other hand, no one can deny that the display of behavior presupposes the action of forces, for, without them, noth- ing would be set in motion and there would be no resistance to be overcome. Voluntary acts are no exception. What is difficult is to determine the type of activating force. As the matter stands, one can only argue by exclusion. Certainly, conditions required for the release of nuclear forces are not present; gravitational forces also are excluded, for today it has been - shown that psychic processes take place normally under conditions of weightlessness. The activating forces could be molecular or electromagnetic. Possibly, as yet undiscovered forces may be active which belong to none of the known categories, forces inherent in the living neuronal system of man and other higher animals. Such a concept may mean, to be sure, a revival of the long- departed vitalistic theory. This suggestion is not so absurd, since the experiments which seem to have ruled out vitalistic processes have concerned only somatic or organic functions. However, psychic functions are a reality for the living individual even though they cannot be objectified by outsiders. Causality and Communication The substitution of verbal symbols for perceptions of reality plays an important role in causal thinking. An example of such substitution is the reporting of a conference, with mention of the names of the participants. To this conference report only a few details need be added to convey meaningful information concerning the course of the transactions and the conclusions reached. Acoustical and optical symbols are also used, moreover, and not only for communication between man and man. A dog reacts to the call of its name as a consequence of its education. It looks about, comes to its master, and responds whenasked, through word and sign, to perform tricks it has learned. In the human, basically complex information can be reduced to symbols of fixed, brief design which denote, nevertheless, wide-reaching conclusions. The highest development is found in the symbols of mathematics. Here, data can be expressed through ciphers and other signs which denote qualitative as well as quantitative aspects, and new insights can be developed. Sense stimulations which are integrated into a pattern of neural excitation are transferred automatically to the environment by the receiving and perceiving subject. This transfer corresponds to the long-known rule of excentric projection. The consequence of this is that no clue concerning Josalization and organization of the ‘nervSCTIESCE, VOL. 158 » sion of inhibition. For this reason the ventures of the inebriate lead all too often to catastrophe. Another group of substances, the amphetamine compounds, also increase initiative and give