to the ordinary course of nature, I may still have sufficient leisure for
this end. But I conceive myself the more bound to husband the time that
remains the greater my expectation of being able to employ it aright, and
I should doubtless have much to rob me of it, were I to publish the
principles of my physics: for although they are almost all so evident that
to assent to them no more is needed than simply to understand them, and
although there is not one of them of which I do not expect to be able to
give demonstration, yet, as it is impossible that they can be in
accordance with all the diverse opinions of others, I foresee that I
should frequently be turned aside from my grand design, on occasion of the
opposition which they would be sure to awaken.

It may be said, that these oppositions would be useful both in making me
aware of my errors, and, if my speculations contain anything of value, in
bringing others to a fuller understanding of it; and still farther, as
many can see better than one, in leading others who are now beginning to
avail themselves of my principles, to assist me in turn with their
discoveries. But though I recognize my extreme liability to error, and
scarce ever trust to the first thoughts which occur to me, yet-the
experience I have had of possible objections to my views prevents me from
anticipating any profit from them. For I have already had frequent proof
of the judgments, as well of those I esteemed friends, as of some others
to whom I thought I was an object of indifference, and even of some whose
malignancy and envy would, I knew, determine them to endeavor to discover
what partiality concealed from the eyes of my friends. But it has rarely
happened that anything has been objected to me which I had myself
altogether overlooked, unless it were something far removed from the
subject: so that I have never met with a single critic of my opinions who
did not appear to me either less rigorous or less equitable than myself.
And further, I have never observed that any truth before unknown has been