12 THE THEORY OF [pt. 



beauteous a structure as the World and the Creatures thereof, was 

 but his Art; but their sundry and divided operations, with their 

 predestinated ends, are from the Treasure of his Wisdom. In the 

 causes, nature, and affections of the EcHpses of the Sun and Moon 

 there is most excellent speculation, but to profound farther, and to 

 contemplate a reason why his providence hath so disposed and 

 ordered their motions in that vast circle as to conjoyn and obscure 

 each other, is a sweeter piece of Reason and a diviner point of 

 Philosophy; therefore sometimes, and in some things, there appears 

 to me as much Divinity in Galen his books De Usu Partium, as in 

 Suarez' Metaphysicks: Had Aristotle been as curious in the enquiry 

 of this cause as he was of the other, he had not left behind him an 

 imperfect piece of Philosophy but an absolute tract of Divinity". 

 This was written in Harvey's time, and in Harvey's thought the four 

 causes were still supreme ; his De Generatione Animalium is deeply con- 

 cerned with the unravelling of the causes which must collaborate in 

 producing the finished embryo. But the end of their domination was 

 at hand, and the exsuccous Lord Chancellor, whose writings Harvey 

 thought so little of, was making an attack on one of Aristotle's causes 

 which was destined to be peculiarly successful. There is no need to 

 quote his immortal passages about the "impertinence", or ir- 

 relevance, of final causes in science, for they cannot but be familiar 

 to all scientific men. Bacon demonstrated that from a scientific point 

 of view the final cause was a useless conception; recourse to it as an 

 explanation of any phenomenon might be of value in metaphysics, 

 but was pernicious in science, since it closed the way at once for 

 further experiments. To say that embryonic development took the 

 course it did because the process was drawn on by a pulling force, 

 by the idea of the perfect adult animal, might be an explanation of 

 interest to the metaphysician, but as it could lead to no fresh experi- 

 ments, it was nothing but a nuisance to the man of science. Later 

 on, it became clear also that the final cause was irrelevant in science 

 owing to its inexpressibility in terms of measurable entities. From 

 these blows the final cause never recovered. In England the seven- 

 teenth century was the time of transition in these aflfairs, and in such 

 books as Josfeph Glanville's Plus Ultra and Scepsis Scientifica, for in- 

 stance, and Thomas Sprat's Defence of the Royal Society, the stormy 

 conflict between the "new or experimental philosophy" and the 

 Aristotelian "school-philosophy" can be easily followed. Francis 



