6 GRAHAM LUSK 



as they devoutly entered into this great heritage. The education of peoples is 

 like that of an individual. It is some time after education in the schools has 

 taught one to think that one is capable of independent action, and usually one 

 seeks first the wrong way before one finds the right. Even so, the change from 

 the olden to the modern could take place only after prolonged struggle. The 

 spirit was gradually sharpened but there were not enough new facts to create 

 new ideas. Satisfaction was sought in acute dialectics. This was only an indi- 

 cation that the old methods brought no one forward. Finally, the tremendous 

 events which took place in the fifteenth century changed dutiful scholars into 

 critics and independent investigators who, through the revelation of heretofore 

 unknown methods of the mind, were able to open up new pathways. 



The Renaissance 



The universities of Cambridge (founded in 1229) and Oxford 

 (founded in 1249) were established at a time when authority was wor- 

 shiped. After the revival of learning in Italy the original versions of 

 the ancient classics were brought into France and England and the for- 

 gotten culture of a bygone civilization was revived. 



The Greek idea of medicine persisted after two thousand years and 

 Chaucer (1340-1400) portrays the physician as follows: 



"He knew the cause of every malady, 

 Were it of cold or hot or moist or dry, 

 And where engendered and of what humour, 

 He was a very perfect practisour." 



No adequate conception of the nature of nutrition was possible with- 

 out an understanding of the nature of air. The idea that air was an ele- 

 mentary substance persisted until comparatively recent times. The grop- 

 ing of human inquiry into the analysis of the invisible atmosphere con- 

 stitutes a fascinating chapter. 



Leonardo da Vinci (1452-1519), accounted one of the greatest paint- 

 ers of the Renaissance and who was at the same time mathematician, 

 physicist and naturalist, said at the end of the fifteenth century that no 

 animal, whether of the land or of the air, could live in an atmosphere 

 which could not support a flame (Milne-Edwards I, 377). The broad 

 mind of Leonardo with won'derful intuition interprets life as follows : 



Hast thou marked Nature's diligence? The body of everything that takes 

 nourishment constantly dies and is constantly reborn ; because nourishment can 

 only enter, into places where that past nourishment has expired, and if it has 

 expired it has no more life; and if you do not supply nourishment equal to the 

 nourishment departed life will fail in vigor; and if you take away this nourish- 

 ment life is utterly destroyed. But if you restore as much as is consumed day 

 by day, just so much of life is reborn as is consumed; as the flame of the candle 

 is fed by the nourishment given by the liquor of the candle, which flame con- 

 tinually with rapid succor restores from below what above is consumed in 



