 is at best we do not know what;—whether something or nothing: and how can the mind lay hold on, or form any accurate abstract idea of such a subtile, fleeting thing?

Disputants (Maria answered) may perplex with deep speculations, and confound with mysterious disquisitions, but the method of fluxions has no dependance on such things. The operation is not what any single abstract velocity can generate or describe of itself, but what a continual and successively variable velocity can produce in the whole: And certainly, a variable cause may produce a variable effect, as well as a permanent cause a permanent and constant effect. The difference can only be, that the continual variation of the effect must be proportional to the continual variation of the cause. The method of fluxions therefore is true, whether we can or cannot conceive the nature and manner of several things relating to them, though we had no ideas of perpetually arising increments, and magnitudes in nascent or evanescent states. The knowledge of such things is not essential to fluxions. All they propose is, to determine the velocity or flowing wherewith a generated quantity increases, and to sum up all that has been generated or described by the continually variable fluxion. On these two bases fluxions stand.
This was clear and just, and shewed that the nature and idea of fluxions is agreeable to the nature and constitution of things. They can have no dependance upon any metaphysical speculations, (such speculations as that

anti-mathematician, my Lord of Cloyne, brought in, to cavil and dispute against principles he understood nothing of, and maliciously run the account of them into the dark;) but are the genuine offspring of nature and truth. An instance or two may illustrate the matter.
•	1. A heavy body descends perpendicularly 16 1/12 feet in a second, and at the end of this time, has acquired a velocity of 32⅙ feet in a second, which is accurately known. At any given distance then from the place the body fell, take the point A in the right line, and the velocity of the falling body in the point may be truly computed: but the velocity in any point above A, at ever so small a distance, will be less than in A; and the velocity at any point below A, at the least possible distance, will be greater than in A. It is therefore plain, that in the point A, the body has a certain determined velocity, which belongs to no other point in the whole line. Now this velocity is the fluxion of that right line in the point A; and with
