What is the overall main idea of the paragraph? Excerpt from An Elementary Study of Chemistry Before we advance very far in the study of nature, it becomes evident that the one large study must be divided into a number of more limited ones for the convenience of the investigator as well as of the student. These more limited studies are called the natural sciences. Since the study of nature is divided in this way for mere convenience, and not because there is any division in nature itself, it often happens that the different sciences are very intimately related, and a thorough knowledge of any one of them involves a considerable acquaintance with several others. Thus the botanist must know something about animals as well as about plants; the student of human physiology must know something about physics as well as about the parts of the body. McPherson, William, and William Edwards Henderson. An Elementary Study of Chemistry. Rev. ed. Boston: Ginn & Company, 1906. Print.