6 ZOOLOGY AS A SCIENCE 



tions are made from the facts observed, rate; one is certain that he was observing 

 Many facts are collected on the topic in the viscera of some lower mammal when he 

 question and after these are all assembled, wrote it. His ideas concerning the function 

 certain conclusions are drawn. The counter- of the various parts of the body are rather 

 part of this method is the deductive method amusing to us today. For example, he 

 of reasoning, wherein the generalization is thought that the brain produced mucus and 

 made and the facts gathered to fit the gen- was cold while the spinal cord was hot, 

 eralization. Most of our great advances in that the heart was the seat of intelligence, 

 science have come from the utilization of and that food "cooked" in the digestive tract, 

 the inductive rather than the deductive Aristotle was convinced that animals 

 method of reasoning. Even when the latter evolved from lower forms, culminating in 

 method is employed certain basic facts, fre- man; thus he laid the foundation for the 

 quently mathematical, are used as a starting theory of evolution, which was to gain a 

 point. While Aristotle was undoubtedly in- foothold over 2,000 years later. He de- 

 fluential in introducing the inductive method scribed 520 species of animals that have 

 of reasoning to the world, even he was de- since been identified. He erected a crude 

 pendent on considerable information that method of classifying animals, altliough his 

 had accumulated during the centuries be- system was not accepted by subsequent tax- 

 fore his time. It cannot be emphasized too onomists. 



strongly that no man, however great, stands Using Aristotle's contribution toward ini- 



out entirely alone. He always depends to tiating the scientific method of approach to 



some extent at least on what preceded him. the solution of problems, some progress was 



Aristotle was a man of considerable in- made by his followers. But the road was 



fluence in his day and his stature grew difficult and progress was extremely 



tremendously for centuries after his death; slow. Of the many men who wrote during 



the student of today could hardly miss his the first few hundred years following Aris- 



name in almost any field of learning, totle, Galen, who lived in the second cen- 



His greatest contribution, perhaps, was tury a.d., was the most outstanding; he 



his method of approaching problems. Not made some rather remarkable contributions 



that he was right in all of his observations, to the anatomical studies of the human 



for he made many mistakes, but it was his body (Fig. 1-2). Aristotle's influence prob- 



constant insistence on making careful ob- ably stimulated Galen to make some accu- 



servations, first hand, and recording them rate observations on the brain and heart 



accurately that was important. To be sure, particularly. He was denied the use of hu- 



he did rely on accounts by his friends or man bodies for dissection, and his writings 



earlier writers for the description of forms indicate that he used the ape and goat for 



he had never seen. For example, he wrote his studies. 



that there were no neck bones in the lion Galen was a voluminous writer, having 



but merely a fused mass extending from the completed 256 treatises during his lifetime, 



thorax to the skull. It is obvious that he had most of which were medical in character, 



not seen a lion's skeleton or he would never Of these his most outstanding were written 



have written this account. However, where on human anatomy. Galen lived at the close 



he made his own observations, such as his of the Age of Classical Culture, just before 



description of the development of the chick, the Middle Ages, in which all learning was 



he was meticulously accurate. The reader is at a standstill. It was fortunate, for the hun- 



impressed by his account of the breeding of dreds of generations of medical men who 



sharks. On the other hand, his description followed, that Galen did produce work of 



of the internal human anatomy is inaccu- such high grade, because it formed the ba- 



