The simplicity and applicability of these pathognomic laws which pervade all psychic phenomena are such that they are easily mastered, and a single evening devoted to the subject enables my students to locate with approximate correctness nearly all the organs of the brain. The multiplicity of the cerebral organs is somewhat discouraging to a student at first, but all embarrassment is removed when the simplicity of the Divine plan is shown. In illustrating these principles, we take up a number of faculties successively, and determine by their nature what should be their latitude and longitude upon the map. Thus, for example, if Modesty is mentioned, students would say it should be above the horizontal line, but not so high as the virtues, and that it should be not among the energies, but among the moderating faculties of the front half of the head. Hence they usually ascertain its true location. If Avarice or Acquisitiveness should be considered, they would recognize it as entitled to a place below the horizontal line, and also behind the vertical line, but neither the lowest nor the most posterior. If Firmness is mentioned, they recognize it as entitled to a high place, but behind the vertical line; and thus they seldom make any great error in determining the location of an organ. [Illustration] If we thus go through the catalogue of psychic powers or qualities, we observe finally that the organs are grouped as follows; and this grouping should be impressed upon the memory, as it is easily learned, and serves as a basis for the further study of organology. The organs in this drawing are not arranged to show their antagonism, but antagonism is the most important fundamental principle of cerebral psychology. THE LAW OF ANTAGONISM. Antagonism or opposition is the universal condition of all that we know. Up suggests down; inward, outward; forward, backward; advance, recession; motion, rest; elevation, degradation; abundance, deficiency; heat, cold; light, darkness; strength, weakness. The same antagonism exists in the psychic nature, as in love, hate; hope, despair; courage, cowardice; pride, humility, etc.; and equally in the physiological, as we see in the action of flexor and extensor muscles, their antagonism being a necessity. If we had only flexor muscles, one motion would exhaust the muscular capacity; when the limb is flexed it can do nothing more; but when the extensor muscle moves it back, flexion can be again performed. Thus all vital voluntary action is a play of opposing forces,--the existence of one force rendering possible the existence of its opposite. The coronal organs, carrying the soul above the body, would bring the end of terrestrial life, and the basilar organs exhausting the brain would bring to a more disastrous end; but the joint action of the two, like that of flexor and extensor muscles, produces the infinite variety of life, which moves on like pendulums, in continual alternation.