If this Discourse appear too long to be read at once, it may be divide into six Parts: and, in the first, will be found variou considerations touching the Sciences; in the second, the principa rules of the Method which the Author has discovered, in the third certain of the rules of Morals which he has deduced from this Method in the fourth, the reasonings by which he establishes the existence o God and of the Human Soul, which are the foundations of his Metaphysic in the fifth, the order of the Physical questions which he ha investigated, and, in particular, the explication of the motion of th heart and of some other difficulties pertaining to Medicine, as als the difference between the soul of man and that of the brutes; and, i the last, what the Author believes to be required in order to greate advancement in the investigation of Nature than has yet been made, wit the reasons that have induced him to write