XVI

An Account os the Life and Writings

thor’s own hand; and we need only add, that as it was of the last, so itappears to have been, in his own judgment, one of the best of his per-formances.

The account of Sir Isaac Newton's philosophy lies now before the reader;who, by casting his eye on the table of contents , may fee the author’s de-( sign and method ; and in perusing the work itself will not, we hope, findhimself disappointed.

' One question however may be put, which it is proper for us to obviate.Why,' in this account, Sir Isaac Newton's grand discoveries concerning lightand colours, are but transiently and in general touched upon ? To this' itis answered, that our author’s main design seems to have been to explainonly those parts of Sir ljaac's philosophy that have been, and are still,controverted. But it is known that, ever since the experiments, on whichhis doctrine of light and colours is founded, have been repeated with duecare, this doctrine has suffered no contestation : Whereas his system ofthe world, his accounting for the celestial motions, and the other greatAppearances of nature, from gravity, is misunderstood and even ridiculedto this day : the weak charge of occult qualities has been frequently repeated;foreign professors still amuse themselves with imaginary triumphs; even thepolite and ingenious Cardinal de Polignac is seduced to lend them the har-mony os his numbers.

It was proper therefore that these Gentlemen sliould once more be told(and by Mr. Maclaurin) that their objections are altogether out of season ;that the spectres they are daily combating are a creation of their own, nomore related to Sir IJaac Newton's doctrines than observation and experienceare to occult qualities; that the followers of Sir IJaac Newton will for everassert their right to stop where they find they can get no farther upon sureground ; and to make use of a principle firmly established in experience,adequate to all the purposes they apply it to, and in every applicationuniform and consistent with itself; * although they, perhaps, despair oftracing the ulterior cause of that principle.

But besides that Sir Isaac Newton's treatise of optics wanted no defence, itmay be said likewise, that it scarce admits of an explication ; it is such an ab-solute ma st er-piece of philosophical writing, that it can as little be abridgedas enlarged; and we had better take all his experiments, illustrations and proofsin the words in which he has delivered them, than risque the injuring themby a different dress. As for the hints which he could not further puisne, and

* Of this we fee a fresh instance ki a stand, admirable discovery of Dr. Bradley s; of a smallnutation of the earth’s axis, from the motion of the nodes of the lunar orbit.

which