Cosmology
The differences between the three philosophers was not limited to the nature of matter. Each of them conceived of the universe differently. Thales held that the Earth was floating in water. Anaximander placed the Earth at the center of a universe composed of hollow, concentric wheels filled with fire, and pierced by holes at various intervals, which appeared as the sun, the moon, and the other stars. For Anaximenes, the sun and the moon were flat disks traveling around a heavenly canopy, on which the stars were fixed.
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