with Thales and he is seen as an incipient matter-and-formist. Thales thought the Earth must be a flat disk which is floating in an expanse of water. Heraclitus Homericus states that Thales drew his conclusion from seeing moist substance turn into air, slime and earth. It seems likely that Thales viewed the Earth as solidifying from the water on which it floated and the oceans that surround it. Writing centuries later, Diogenes Laërtius also states that Thales taught "Water constituted (, 'stood under') the principle of all things." Aristotle considered Thales’ position to be roughly the equivalent to the later ideas of Anaximenes, who held that everything was composed of air. The 1870 book Dictionary of Greek and Roman Biography and Mythology noted: Beliefs in divinity According to Aristotle, Thales thought lodestones had souls, because iron is attracted to them (by the force of magnetism). Aristotle defined the soul as the principle of life, that which imbues the matter and makes it live, giving it the animation, or power to act. The idea did not originate with him, as the Greeks in general believed in the distinction between mind and matter, which was ultimately to lead to a distinction not only between body and soul but also between matter and energy. If things were alive, they must have souls. This belief was no innovation, as the ordinary ancient populations of the Mediterranean did believe that natural actions were caused by divinities. Accordingly, Aristotle and other ancient writers state that Thales believed that "all things were full of gods." In their zeal to make him the first in everything some said he was the first to hold the belief, which must have been widely known to be false. However, Thales was looking for something more general, a universal substance of mind. That also was in the polytheism of the times. Zeus was the very personification of supreme mind, dominating all the subordinate manifestations. From Thales on, however, philosophers had a tendency to depersonify or objectify mind, as though it were the substance of animation per se and not actually a god like the other gods. The result was a total removal of mind from substance, opening the door to a non-divine principle of action. Classical thought, however, had proceeded only a little way along that path. Instead of referring to the person, Zeus, they talked about the great mind: The universal