By 1480 , he was in Venice , where he wrote Quaestio utrum mundus sit effectus .
By 1480 , he supported himself by giving classes in Aristotelian philosophy attended by the sons of wealthy and important families .
By 1480 , he was in Venice , where he wrote Quaestio utrum mundus sit effectus , and supported himself by giving classes in Aristotelian philosophy attended by the sons of wealthy and important families .