The version quoted here, from the 1718 edition, is very close to the Latin, but was probably written in English by Newton. 3 The Latin version, provided by the translator of the Optice, Samuel Clarke, was presumably based on an English original provided by Newton. 2 The remarkable concern with morality and religion is first introduced in the Latin edition of 1706, in the last of seven new queries added to that edition. Accordingly, this is not to be found at the end of the first edition of 1704, which ends with Query 16. These are the final words of Query 31, and therefore of the Opticks itself, as they appear in the second English edition.

And no doubt, if the Worship of false Gods had not blinded the Heathen, their moral Philosophy would have gone farther than to the four Cardinal Virtues and instead of teaching the Transmigration of Souls, and to worship the Sun, and Moon, and dead Heroes, they would have taught us to worship our true Author and Benefactor. For so far as we can know by natural Philosophy what is the first Cause, what Power he has over us, and what Benefits we receive from him, so far our Duty towards him, as well as that towards one another, will appear to us by the Light of Nature. And if natural Philosophy in all its Parts, by pursuing this Method, shall at length be perfected, the Bounds of Moral Philosophy will be also enlarged. In this third Book I have only begun the Analysis of what remains to be discover'd about Light and its Effects upon the Frame of Nature, hinting several things about it, and leaving the Hints to be examin'd and improv'd by the farther Experiments and Observations of such as are inquisitive.

Opticks by isaac newton