The same preface contains Sydenham’s opinion of a great contemporary and valued friend of his. “You know also how thoroughly an intimate and common friend, and one who has closely and exhaustively examined the question, agrees with me as to the method I am speaking of—a man who, in the acuteness of his intellect, in the steadiness of his judgment, in the simplicity (and by _simplicity_ I mean _excellence_) of his manners, has amongst the present generation few equals and no superiors. This praise I may confidently attach to the name of John Locke.” Dugald Stewart, commenting on this, says: “The merit of the Method therefore may be presumed to have belonged in part to Mr. Locke.” There is no reason, however, in the co-operation of these great minds, for detracting from the praise of either. Sydenham’s idea of a satisfactory method of curing was a line of practice based upon a sufficient number of experiments. His business was, he says, to support his own observations, not to discuss the opinions of others. The facts would speak for themselves, and would alone show whether he acted with truth and honesty, or, like a profligate and immoral man, was to be a murderer even when in his grave. In the preface to the third edition he says, “The breath of life would have been to me a vain gift, unless I contributed my mite to the treasury of physic.” He considered that medicine was to be advanced in two main ways—by a history of diseases, by descriptions at once graphic and natural, and by formulating a praxis or method of treating them. The most modern thought could produce no sounder principle for describing disease than the following: “In writing the history of a disease, every philosophical hypothesis whatsoever that has previously occupied the mind of the author should lie in abeyance. This being done, the clear and natural phenomena of the disease should be noted—these and these only. These should be noted accurately and in all their minuteness.” He wittily remarks that it often happens that the character of the complaint varies with the nature of the remedies, and that symptoms may be referred less to the disease than to the doctor. He traces the lack of accurate descriptions of diseases to an idea that disease was but a confused and disordered effort of nature defending herself in vain, so that men had classed the attempts at a just description with the attempts to wash blackamoors white.