For we have not beheld all things, nor yet the true extent of them, but our eyesight does but open to itself the right path for research, and lay the foundation, from which our speculations may pass from what is obvious to what is less known, and find out something more ancient than the world itself, from whence those stars came forth: inquire what was the condition of the universe before each of its elements were separated from the general mass: on what principle its confused and blended parts were divided: who assigned their places to things, whether it was by their own nature that what was heavy sunk downwards, and what was light flew upwards, or whether besides the stress and weight of bodies some higher power gave laws to each of them: whether that greatest proof that the spirit of man is divine be true, the theory, namely, that some parts and as it were sparks of the stars have fallen down upon earth and stuck there in a foreign substance.