Manifestations of life depend on a continuous interplay of natural forces. Worms and elephants, mosquitoes and eagles, plankton and whales display a variety of activities on the land, in the air, and in the sea with a purpose or lack of it-which escapes human understanding, obeying sets of laws which antedate the appearance of human intelligence. In the animal kingdom, existence of the genetic code represents a biological determination of anatomical and functional characteristics in the newborn. The growth and development of organisms after birth proceed according to a natural fate imposed by the correlations between individual structure and environmental circumstances. The fact that about 300 million years ago all the world’s creatures lived in the sea did not depend on their own volition but on biological evolution and ecological factors. The appearance of dinosaurs 180 million years ago in the Triassic period, their supremacy on earth, and their peak in power 30 million years later were determined not by the will of these animals, which had disproportionately small brains and were probably ·rather stupid, but by a propitious warm and sticky climate which provided a soft slosh of water everywhere and land covered with a tangle of greenery, juicy palms, and huge fern like trees extending almost to the North Pole.