Plant and animal physiologists who want to establish a respectable lineage for their disciplines see Stephen Hales as a 'father figure'. For them, Hales was a 'pioneer' in the investigation of transpiration in plants and blood pressure in animals. He is also supposed to have 'anticipated' the work of Antoine Laurent Lavoisier and Joseph Priestley on pneumatic chemistry. Even the recent biography of Hales by Allan and Schofield (1980)1 perpetuates these traditional views. We still do not have an exposition of (...) what Hales' 'statical way' was, why he thought of it, and why and how he applied it as he did. In this study I have used Hales' Statical Essays as the key to his thought and have tried, through them, to present the work of Stephen Hales on his own terms rather than on ours. (shrink)