As for the symbols on our seal, whether they are a dove or a fish or a ship blown by the wind or a musical lyre, like the one that Policrate had, or a ship anchor as Seleuco carried engraved, or finally, if one is a fisherman, he will remember the apostle and the children saved from the waters.
(Clemente Alessandrino – Pedagogo, III, 11, 59)