In respect, then, to brain structure and the more important mental faculties we find that no race is radically unlike the others. Still, it might happen that the mental activities and products of two groups were so different as to place them in different classes. But precisely the contrary is true. There is in force a principle called the law of parallelism in development, according to which any group takes much the same steps in development as any other. The group may be belated, indeed, and not reach certain stages, but the ground patterns of life are the same in the lower races and in the higher. Mechanical inventions, textile industries, rude painting, poetry, sculpture, and song, marriage and family life, organization under leaders, belief in spirits, a mythology, and some form of church and state exist universally. At one time students of mankind, when they found a myth in Hawaii corresponding to the Greek story of Orpheus and Eurydice, or an Aztec poem of tender longing in absence, or a story of the deluge, were wont to conjecture how these could have been carried over from Greek or Elizabethan or Hebraic sources, or whether they did not afford evidence of a time when all branches of the human race dwelt together with a common fund of sentiment and tradition. But this standpoint has been abandoned, and it is recognized that the human mind and the outside world are essentially alike the world over; that the mind everywhere acts on the same principles; and that, ignoring the local, incidental, and eccentric, we find similar laws of growth among all peoples. The number of things which can stimulate the human mind is somewhat definite and limited. Among them, for example, is death. This happens everywhere, and the death of a dear one may cause the living to imagine ways of being reunited. The story of Orpheus and Eurydice may thus arise spontaneously and perpetually, wherever death and affection exist. Or, there may be a separation from home and friends, and the mind runs back in distress and longing over the happy past, and the state of consciousness aroused is as definite a fact among savages as among the civilized. A beautiful passage in Homer represents Helen looking out on the Greeks from the wall of Troy and saying: And now behold I all the other glancing-eyed Achaians, whom well I could discern and tell their names; but two captains of the host can I not see, even Kastor tamer of horses and Polydukes the skilful boxer, mine own brethren whom the same mother bare. Either they came not in the company from lovely Lakedaimon; or they came hither indeed in their seafaring ships, but now will not enter into the battle of the warriors, for fear of the many scornings and revilings that are mine.[261]