Maimonides answered an inquiry concerning astrology, addressed to him from Marseilles. He responded that man should believe only what can be supported either by rational proof, by the evidence of the senses, or by trustworthy authority. He states that he has studied astrology and that it does not deserve to be described as a science. He ridicules the idea that a man's fate could depend on the constellations, arguing that such a theory would rob life of purpose and would make man a slave of destiny.