LUDWIG AND MODERN PHYSIOLOGY. 3 



conception which is more free from doubt either as to its 

 meaning or reality. It is inseparable from that of Life 

 itself, which is but the unfolding of a predestined harmony, 

 of a prearranged consensus and synergy of parts. 



The other branch of Biology, that with which Ludwig's 

 name is associated, deals with the same facts in a different 

 way. While Ontology regards animals and plants as in- 

 dividuals and in relation to other individuals, Physiology 

 considers the processes themselves of which life is a complex. 

 This is the most obvious distinction, but it is subordinate to 

 the fundamental one, namely, that while Ontology has for 

 its basis laws which are in force only in its own province, 

 those of Evolution, Descent, and Adaptation, we Physiolo- 

 gists, while accepting these as true, found nothing upon them, 

 using them only for euristic purposes, i.e., as guides to dis- 

 covery, not for the purpose of explanation. Purposive Adapta- 

 tion, for example, serves as a clue, by which we are constantly 

 guided in our exploration of the tangled labyrinth of vital 

 processes. But when it becomes our business to explain 

 these processes — to say how they are brought about — we 

 refer them not to biological principles of any kind, but to 

 the Universal Laws of Nature. Hence it happens that 

 with reference to each of these processes, our inquiry is 

 rather how it occurs than why it occurs. 



It has been well said that the Natural Sciences are the 

 children of necessity. Just as the other Natural Sciences 

 owed their origin to the necessity of acquiring that control 

 over the forces of Nature without which life would 

 scarcely be worth living, so Physiology arose out of human 

 suffering and the necessity of relieving it. It sprang indeed 

 out of Pathology. It was suffering that led us to know, as 

 regards our own bodies, that we had internal as well as 

 external organs, and probably one of the first generalisa- 

 tions which arose out of this knowledge was, that " if one 

 member suffer all the members suffer with it " — that all 

 work together for the good of the whole. In earlier times 

 the good which was thus indicated was associated in men's 

 minds with human welfare exclusively. But it was 

 eventually seen that Nature has no less consideration for 



