PREFACE

TO THE READER.

You now have, learned reader, in this book on Natural Motions Depending on Gravity, together with the previous book on The Force of Percussion, everything that should have been presented first for a perfect understanding of the theory of the movements of animals original: "animalium motibus"; Borelli considered physics and mechanics to be the necessary foundation for biology. This is with the exception of many mechanical lemmas A lemma is a preliminary proposition used to prove a larger theorem or provide a stepping stone in an argument., which will be explained in their proper places later according to the requirements of the subject.

I must, however, say a few things beforehand about this work and the previous one. In these books, views are often brought forward that differ from the opinions of authors with great names. I have done this with the greatest modesty and moderation. I pursue the ideas, but I do not attack the names or reputations of the authors. I seek only the truth, while preserving the dignity and fame of very distinguished men.

This is clear from the fact that I only list the names of living authors when an opportunity to praise them is offered. When controversies are debated, the names of the authors are entirely hidden and kept silent. Because I could not escape the biting remarks of critics even with this careful moderation and modesty, I have decided to promise once again that I will not be moved from my chosen path. I do not wish to publish any defensive or argumentative response to opponents, if any should happen to exist. Instead, if it is necessary, I will only explain my teaching more clearly, or correct it where I might have made a human error. Farewell.