If a nonnegative quantity was so small that it is smaller than any given one, then it certainly could not be anything but zero. To those who ask what the infinitely small quantity in mathematics is, we answer that it is actually zero. hence there are no so many mysteries hidden in this concept as they are usually believed to be. These supposed mysteries have rendered the calculus of the infinietly small quite suspect to many people. Those doubts that remain we shall thoroughly remove....
Swiss mathematician, 1707-1783