26 Introduction 



"What is the good of it? Who will read the stu£F, and who will preserve 

 it?" Such reticence as opposed to the cacoethes scribendi which is one 

 of the diseases of our time, was probably one of the causes of the slow- 

 ness of progress in antiquity. The relationship of Ptolemy (II-l) to 

 HiPPARCHOs (II-2 B.C.) is like that of a younger contemporary to his 

 senior, yet they were separated by almost three centuries. Much knowl- 

 edge has failed to reach us because of the silence of the inventors, or of 

 their lost pains if they broke it. After all a discovery hardly counts if 

 it be not published; the tradition of a discovery is second in importance 

 to the discovery itself. 



The history of ancient and mediaeval science is very largely a history 

 of traditions. The discoveries and inventions are not many, because the 

 laborers were few as compared with to-day and because the progress of 

 science is naturally an accelerated one (hence if we look backward the 

 acceleration is negative). The enumeration and discussion of those 



riGURE 1 



discoveries are relatively brief; on the other hand, it is very difficult to 

 explain their tradition (without which they would be as if they had 

 never been) and this requires considerable space. The tradition was 

 oral, written or manual; the last one is the most difficult to deal with 

 in accurate detail. We can only speak of it in general and infer it from 

 the results; it is like an underground river which remains hidden for 

 long stretches, yet we can be reasonably certain that the river emerging 

 from the earth at a point B is the same as disappeared at another point 

 A many miles distant. Much of the knowledge of craftsmen, physicians, 

 alchemists, and perhaps their most valuable knowledge, was trans- 

 mitted by manual examples to their apprentices. The master would 

 say "Watch me, see what I am doing and how I am doing it, and try 

 to do the same." 



We might attempt a graphical representation of these views. The 

 tradition of each single idea or fact might be symbolized by a line, more 

 or less regular, with ups and downs. Some of these lines are interrupted 

 because the tradition has ceased for a time to be visible. Sometimes 

 the lines cross and their intersections may be indifferent or they may 

 correspond to a knot or new discovery (Fig. 1). 



