In classical Greece, Anaxagoras asserted that a divine reason (mind) gave order to the seeds of the universe, and Plato extended the Greek belief of ideal forms to his metaphysical theory of forms (ideai, "ideas"). The forms on earth are imperfect duplicates of the intellectual celestial ideas. The Greek words oida (οἶδα, "(I) know") and eidos (εἶδος, "species") have the same root as the word idea (ἰδέα), indicating how the Greek mind moved from the gift of the senses, to the principles beyond the senses. The artists in Plato's time moved away from his theories and art tends to be a mixture of naturalism with stylization. The Greek sculptors considered the senses more important, and the proportions were used to unite the sensible with the intellectual.