Lawrence took occasion, in his first lectures in 1816, to criticise Abernethy’s exposition of Hunter’s theory of life, and to unfold views which seriously scandalised those who regarded life as a mysterious entity entirely separate from and above the material organism with which it is associated. These views were criticised by Abernethy in his “Physiological Lectures” in 1817, and Lawrence replied in 1818, in terms of sarcasm which made a serious breach between the master and his former pupil. Lawrence’s lectures were published as “An Introduction to Comparative Anatomy and Physiology,” 1816, and “Lectures on Physiology, Zoology, and the Natural History of Man,” 1819. Having been accused by Abernethy and others “of perverting the honourable office intrusted to him, by the College of Surgeons, to the very unworthy design of propagating opinions detrimental to society, and of endeavouring to enforce them for the purpose of loosening those restraints on which the welfare of mankind depends,” he used his eloquence unsparingly both to defend his position, and to repel the attacks made upon him. He was not more heretical than many of his predecessors, nor than a great many enlightened biologists of the present day. He regarded life as “the assemblage of all the functions, and the general result of their exercise. Thus organisation, vital properties, functions and life, are expressions related to each other; in which organisation is the instrument, vital properties the acting power, function the mode of action, and life the result.” Again, “we find that the motion proper to living bodies, or in one word, Life, has its origin in that of their parents. From their parents they have received the vital impulse, and hence it is evident, that in the present state of things, life proceeds only from life; and there exists no other but that which has been transmitted from one living body to another by an uninterrupted succession.”