ABSTRACT
The life of man may be viewed in many different ways. He may be viewed as one species of mammal and considered in a purely biological light. From this point of view his success has been overwhelming. He can live in all climates and in every part of the world where there is water. His numbers have increased and are increasing still faster. He owes his success to certain things which distinguish him from other animals: speech, fire, agriculture, writing, tools, and large-scale co-operation.
