Q.E.D. But it is plain that the direct and true Method to obtain the Moment or Increment of the Rectangle AB, is to take the Sides as increaſed by their whole Increments, and ſo multiply them together, A + a by B + b, the Product whereof AB + aB + bA + ab is the augmented Rectangle whence if we ſubduct AB, the Remainder aB + bA + ab will be the true Increment of the Rectangle, exceeding that which was obtained by the former illegitimate and indirect Method by the Quantity ab. And this holds univerſally be the Quantities a and b what they will, big or little, Finite or Infiniteſimal, Increments, Moments, or Velocities. Nor will it avail to ſay that ab is a Quantity exceeding ſmall: Since we are told that in rebus mathematicis errores quàm minimi non ſunt contemnendi.[1] Such reaſoning as this, for Demonſtration, nothing but the obſcurity of the Subject could have encouraged or induced the great Author of the Fluxionary Method to put upon his Followers, and nothing but an implicit deference to Authority could move them to admit. The Caſe indeed is
- ↑ Introd. ad Quadraturam Curvarum.
