550 PHILOSOPHICAL TRANSACTIONS. [aNNO ISQS. 



He held also the rotation of the earth, as also the annual motion about the 

 middle of the world. To show the reason why it is so difficult to find what 

 were their true thoughts, the author quotes this passage of Plutarch : this doc- 

 trine (that is, concerning the heavens) was not celebrated and famous, but 

 hidden and kept secret, and it was discoursed of with great caution among a 

 few, under an oath of secrecy ; for philosophisings concerning the heavens 

 would not be endured, because those seemed to restrain and bind up the divine 

 numen to causes without reason, and to blind powers, and to involuntary 

 effects ; on which account Protagoras was banished, and Anaxagoras put in 

 irons. Socrates also, for the name of a philosopher, was put to death. Whence 

 the author observes, that in all ages it has been very dangerous for philosophers 

 to speak plain truth among the vulgar. 



In the 11th chapter he inquires concerning the doctrine of Pythagoras and 

 the Italic philosophy ; where he finds that either Pythagoras wrote nothing, or 

 if he did, even the history of them is lost ; so that nothing of his physiology is 

 remaining, save only his theory of the heavens, which is called the Pythagoric. 

 system ; he placing the sun in the centre, and the earth moving round it ; the 

 moon is an anticthone or opposite earth enlightened by the sun, the comets to 

 be above the air, or between that and the planets ; that the heavens were fluid 

 aether, and the stars so many worlds. 



In the 12th chapter he inquires concerning the opinions of the Eleatic sect, 

 and of the Stoics. This sect was founded by Zenophanes in the times of Anaxi- 

 mander, and consisted of a mixture of various nations and opinions. The doc- 

 trine he held was, that there were infinite suns and infinite moons like ours, 

 which he said were habitable, but that they were all eternal. Parmenides held 

 them to be formed out of fire and earth, and men out of clay. They agreed 

 much with the Ionic sect. Leucippus and Democritus were of this sect, who 

 introduced atoms. Leucippus acknowledged the motion of the earth on its axis, 

 and that when the fluid mass settled into a globe, it was covered by a dry skin, 

 which growing thicker, formed the habitable earth ; he supposes the axis also 

 at first right, but altered afterward ; both which are consonant to the author's 

 theory. 



In the 13th chapter the author inquires among the Platonics, Aristotelians, 

 and Epicureans. First, he finds the Platonics, like the Pythagoreans, to be 

 most taken up in high speculations of abstract notions, and in assigning causes 

 of things to numbers and geometrical figures. Thus Plato in his Timaeus 

 makes nothing visible but fire, nothing tangible but earth, between these two 

 for their own union are placed air and water. The solid badies he supposes 

 made up of triangles ; fire he makes of pyramids, consisting of four triangles ; 



