Now after he had attained thus far, so as to have a general and indistinct notion of an _Agent_, a vehement desire seized him to get a more distinct knowledge of him. But since he had not yet withdrawn himself from the sensible world, he began to look for this voluntary Agent among things sensible; nor did he know, as yet, whether it were one Agent or many. Therefore he took a view of all the bodies that were near him, viz. which his thoughts had been continually fixed upon; which he found all successively liable to generation and corruption, either completely or in parts, as _water_ and _earth_, parts of which are consumed by _fire_. He perceived likewise that the air was changed into snow by extremity of cold, and then again into water; and among all the other bodies which he had near him, he could find none which had not its existence anew and required some voluntary Agent to give it a being. Therefore he laid all those sublunary bodies aside, and transferred his thoughts to the consideration of the heavenly bodies. THE FOURTH SEPTENARY. _Hayy ponders over Heaven and Stars._ Thus far had he arrived with his reflections about the _fourth septenary_ of his age. He recognised that the heavens and all the stars contained therein were bodies, because they are extended according to the three dimensions: length, breadth, and thickness. Then he began to ask himself whether their extension was infinite, whether they extended to an endless length and breadth, or whether they were circumscribed by any bounds and terminated by certain limits. _Hayy finds that the Body of Heaven is finite._ This problem continually occupied his mind. But soon, owing to the power of his reflection and the penetration of his thought, he perceived that the idea of an infinite body was an absurdity, an impossibility, a notion quite unintelligible. And he confirmed himself in this way of thinking by numerous arguments that presented themselves to his mind. And when, by the singular sharpness of his wit, he had satisfied himself that the body of heaven was finite, he wanted to find out, in the next place, of what form it was and how it was limited by the superficies that compassed it round. _Hayy contemplates Sun, Moon, and Stars._ First of all he contemplated the sun, moon, and stars, and saw that they all rose in the East, and set in the West; and those lights which went right over his head described a greater circle, whilst those at a greater distance from the vertical point towards the North or South described the lesser circle. So that the least circles which were described by any of the stars were those two which went round the two poles, the one North, the other South, the last of which is the circle of the star Suhail (that is Canopus) and the circle Al-farkadani, which was next the northern.