The author of this precept "never stand surety" is Thales of Miletus (Θαλῆς ὁ Μιλήσιος), whose name has survived through the centuries. Greek philosopher and scholar, born in Miletus around 625-620 BC, died around 548-545 BC, still in Miletus, he is best known for his scientific reasoning! Legend has it that this mathematician and philosopher of nature spent time in Egypt, where he was initiated into Egyptian and Babylonian science through the teachings of the priests.