IX 
PREFACE. 
It is true this does not always happen to 
the fearcher, or his contemporaries, nor 
even, fometimes to the immediate fucceed- 
ing generation ; but i am apt to think that 
advantages of one kind or other always ac- 
crue to mankind from fuch purfuits. Some 
men are born to obferve and record what 
perhaps by itfelf is perfectly ufelefs, but 
yet of great importance, to another who 
follows and goes a ftep farther ftill as ufe- 
lefs. To him another fucceeds, and thus 
by degrees ; till at laft one of a fuperior 
genius comes, who laying all that has been 
done before his time together brings on a 
new face of things, improves, adorns, ex- 
alts human fociety. 
All thofe fpeculations concerning lines 
and numbers fo ardently purfued, and fo 
exquiiitely conducted by the Grecians ; 
what did they aim at ? or what did they 
produce for ages ? A little arithmetic, and 
the firft elements of geometry were all 
they had need of. This Plato afferts, and 
tho’ as being himfelf an able mathematician 
and remarkably fond of thefe fciences, he 
re- 
