Review of the Principia of Newton. 239 
whether of old or new works, may be made the instruments 
of conveying knowledge to the less informed, on subjects to 
which they have no access, or which, in the works them- 
selves, would be above their comprehension. ‘There is, 
moreover, a particular advantage resulting from an analysis 
of old standard works, which consists in comparing the in- 
ventions and discoveries of our progenitors with those which 
plagiaries and pretenders have obtruded on the present gene- 
ration, as their own. It is basely iniquitous and ee that 
men should shine by the reflected light of others 
) 
state of the sciences, one must be possessed of great learning 
to be able to detect all the sources of plagiarism : but on par- 
ticular subjects, to which he has devoted his principal ener- 
gies, it may reasonably be supposed that he is competent to ; 
uch an undertaking: at any rate, discussion will elicit 
anti the only object which a truly scientific man has in 
view. With such impressions, I enter with difiidence on the 
task of gate Si which acknowledgedly is the most 
ous on of the humana mind, — ever has 
appeared on aaa viz. the Principia of Newt 
It is generally known, that before the time of Lord Bacon, 
even from the remotest period, little or no improvements had 
made in Natural Philosophy, the cause of which is not 
pischscatale to the want of ardour in the ancients for that 
science, who, it is believed, in that particular far surpassed 
the moderns ; but to an erroneous system of philosophizing, 
established by Aristotle, and cde Plato tonic School, which 
consisted in deriving physical pr jey.hiad those 
of the mathematics, merely from r intellecteal relations. 
did not consider, that those of the latter science were eternal 
and immutable in their nature, and necessarily connected 
with the ultimate resort of truth in the bane et and eu 
the others were contingent, and dependent only on an 
of things externally existing, and unconnected directly Sis 
intel al relations of the pacer This system, 
however, of mental ees maintained by the authority of 
ames, held possession of the schools 3 2000 aoa 
until the time of the abe pove saenionet ted reform 
The genius of this great man first dared to bicale the hod 
les, which the authority of names and So had imposed 
en the world. He clearly perceived that the operative prin- 
