INFLUENCE OF ABSTRACT THOUGHT 23 



the workshop. Even in the ripening of fruits heat ap- 

 pears to him to have a cooking effect. Heat distorts 

 articles made of potters' clay after they have been 

 hardened by cold. Again we find him describing the 

 manufacture of potash and of steel. He is not disdain- 

 ful of the study of the lower animals, but invites us 

 to investigate all forms in the expectancy of discover- 

 ing something natural and beautiful. In a similar 

 spirit of scientific curiosity the Aristotelian work 

 The Problems studies the principle of the lever, the 

 rudder, the wheel and axle, the forceps, the balance, 

 the beam, the wedge, as well as other mechanical 

 principles. 



In Aristotle, in fact, we find a mind exceptionally 

 able to form clear ideas, and at the same time to 

 observe the rich variety of nature. He paid homage 

 both to the multiplicity and the uniformity of na- 

 ture, the wealth of the phenomena and the simplicity 

 of the law explaining the phenomena. Many general 

 and abstract ideas (category, energy, entomology, 

 essence, mean between extremes, metaphysics, me- 

 teorology, motive, natural history, principle, syllo- 

 gism) have through the influence of Aristotle become 

 the common property of educated people the world 

 over. 



Plato was a mathematician and an astronomer. 

 Aristotle was first and foremost a biologist. His 

 books treated the history of animals, the parts of 

 animals, the locomotion of animals, the generation of 

 animals, respiration, life and death, length and short- 

 ness of life, youth and old age. His psychology is, 

 like that of the present day, a biological psychology. 

 In his contributions to biological science is rnani- 



