the stars make a man a murderer or a thief, then all the more it is the first cause, God, who does this, which it is shameful to suggest". Ptolemy's comments counter the criticism by proposing that whilst the celestial cycles are entirely reliable and "eternally performed in accordance with divine, unchangeable destiny", all earthly things are also subject to "a natural and mutable fate, and in drawing its first causes from above it is governed by chance and natural sequence". He therefore declares that nothing is irrevocably ordained, and we are not to imagine that "events attend mankind as the result of the heavenly cause as if … destined to take place by necessity without the possibility of any other cause whatever interfering". In this discussion Ptolemy makes a point that was to be called upon by many later astrological writers, that "the lesser cause always yields to the stronger". He sees an individual as unable to resist the greater cycles of change which happen to the wider community, so even a man whose horoscope indicates gain may perish at a time that his community is struck by natural disaster or pestilence. However, Ptolemy also maintains that disastrous events will only follow a natural course if no counter action is taken to avert the problem, as when "future happenings to men are not known, or if they are known and the remedies are not applied". He takes a balanced position in the argument of fate versus free will in writing that certain things, because their effective causes are numerous, become inevitable, whilst others are able to be averted by the act of astrological prediction. The astrologer's position is compared to that of the physician, who must be able to recognise beforehand which ailments are always fatal, and which admit of aid. It is therefore reasonable, in Ptolemy's estimation, to moderate actions with awareness of how the prevailing and future temperament prospers or injures the natal temperament, or to elect to act at a time that is astrologically suitable to the activity – just as it is deemed rational to use knowledge of the stars to ensure safety at sea; to use knowledge of the lunar cycle to ensure successful breeding and sowing, or to cool ourselves against the extremes of temperature in order that we suffer less. Ptolemy's philosophical conclusion on the subject, which helped to secure its intellectual