INTRODUCTION. 11 



labor, of which the limits are here defined, arises from the 

 sublime consciousness of striving toward the infinite, and of 

 grasping all that is revealed to us amid the boundless and 

 inexhaustible fullness of creation, development, and being. 



This active striving, which has existed in all ages, must 

 frequently, and under various forms, have deluded men into 

 the idea that they had reached the goal, and discovered the 

 principle which could explain all that is variable in the or- 

 ganic world, and all the phenomena revealed to us by sen- 

 suous perception. After men had for a long time, in accord- 

 ance with the earliest ideas of the Hellenic people, vener- 

 ated the agency of spirits, embodied in human forms,* in the 

 creative, changing, and destructive processes of nature, the 

 germ of a scientific contemplation developed itself in the 

 physiological fancies of the Ionic school. The first principle 

 of the origin of things, the first principle of all phenomena, 

 was referred to two causes! either to concrete material prin- 

 ciples, the so-called elements of Nature, or to processes of 

 rarefaction and condensation, sometimes in accordance with 

 mechanical, sometimes with dynamic views. The hypothe- 

 sis of four or five materially differing elements, which was 

 probably of Indian origin, has continued, from the era of the 

 didactic poem of Empedocles down to the most recent times, 

 to imbue all opinions on natural philosophy a primeval evi- 

 dence and monument of the tendency of the human mind 

 to seek a generalization and simplification of ideas, not only 

 with reference to the forces, but also to the qualitative na- 

 ture of matter. 



In the latter period of the development of the Ionic phys- 

 iology, Anaxagoras of Clazomense advanced from the postu- 

 late of simply dynamic forces of matter to the idea of a spirit 

 independent of all matter, uniting and distributing the homo- 

 geneous particles of which matter is composed. The world- 

 arranging Intelligence (vovg) controls the continuously pro- 

 gressing formation of the world, and is the primary source 



* In the memorable passage (Metaph., xii., 8, p. 1074, Bekker") in 

 which Aristotle speaks of " the relics of an earlier acquired and subse- 

 quently lost wisdom," he refers with extraordinary freedom and sig- 

 nificance to the veneration of physical forces, and of gods in human 

 forms : " much," says he, " has been mythically added for the persua* 

 tion of the multitude, as also on account of the laws and for other useful 

 ends." 



t The important difference in these philosophical directions rpdiroi, 

 is clearly indicated in Arist., Phys. Auscult., 1, 4, p. 187, Bekk. (Com- 

 pare Brandis, in the Rhein. Museum fur Philologie, Jahrg. iii., 8. 105.) 



