1) Figure of the earth as a geometrical problem. In anoient times,people thought that the surface of the earth is essentially flat. This notion hadbeen kept in the minds of the primitive peoples until the beginning of the sixthcentury before Ohrist. The first clear and unequivocal statement of the sphericity of the earth was due to the Greek philosopher Pythogoras (died 582 B. C.). 1) Figure of the earth as a geometrical problem. In anoient times, people thought that the surface of the earth is essentially flat. This notion hadbeen kept in the minds of the primitive peoples until the beginning of the sixthcentury before Ohrist. and unequivocal statement of the sphericity of the earth was due to the Greek philosopher Pythogoras (died 582 BC).