chapter  IV
The Logic of Aristotle
Pages 16

The dualism established by Plato between the world of the senses and the world of ideas failed to satisfy his great disciple Aristotle (384-322 B.c.) (I), who worked out a criticism of the Platonic ideas, observing, among other things, that if ideas constitute a world completely separate from the sensible one, they cannot be its essence, or furnish an explanation of it. According to Aristotle, universal concepts and ideas form the essence of things, and the said ideas are taken from the mind, having their origin in sensible data. We cannot delay over a minute examination of the Aristotelean theory on the origin of ideas ; it will suffice to say that this theory is neither innate, nor simply empirical, and it is happily expressed in the formula of the Renaissance Aristotelian Patrizi : 'Cognitio omnis a mente primam originem, a sensibus exordium habet primum'(2).