196 



GREEK PHILOSOPHY. 



Cohesion 



Perception 



Their 

 poSbie e 



Their 

 necessity. 



images 



produce 

 hearing. 



From earliest time, through ever-during space, 

 \^th ceaseless repercussion, every mode 

 Of motion, magnitude, and shape essayed ; 

 At length th' unwieldy mass the form assumed 

 Of things created. l 



Epicurus's notion of the constitution of matter is thus essentially 

 different from ours. Instead of bodies owing their consistency to the 

 mutual attraction of their particles, he considered them as held together 

 by the shocks and resistance of surrounding atoms. We can thus un- 

 derstand the earnestness with which he labours to prove the infinite 

 extension of matter, and the horror with which an Epicurean looked 

 upon the heresy of one finite world, and of any space altogether empty 

 of matter : 



For once to act, when primal atoms fail, 



Fail where they may, the doors of death are ope, 



And the vast whole unbounded ruin whelms. 2 



Images. 



A prominent feature in Epicurus's philosophical system is the doc- 

 trine ^ perception by images (3wXa). Their nature and the proofs 

 of their existence are thus stated : 



" There exist forms of solid objects, similar to those objects in shape, 

 but differing from them much in the thinness of their substance. For 

 there is no impossibility in such emanations existing in the air, or in 

 there being a capacity in bodies for forming such hollow, thin spectra, 

 or in the emanations retaining the unbroken disposition and structure 

 that they had in the solids. To these forms we give the name of 

 images." 



These images move with inconceivable rapidity, owing to the tenuity 

 of their substance, which encounters little or no resistance in space. 

 They are incessantly streaming off from the surface of all bodies, and 

 are necessary to bring us into rapport with the world without. 



" For external things could not impress upon us their nature, as to 

 co ] our an d shape, through the medium of the air between us and them, 

 or through rays or any other emanations proceeding from us to them ; 

 so that perception must take place as it were through certain forms, 

 of the same colour and shape, and of proportionate size, coming from 

 the objects, and making their way with great rapidity to the eye or 

 the mind." 



In like manner sounding bodies throw off emanations, by which we 



Primordia rerum * * 



* * quia multa modis multis mutata per omne 

 Ex infinite vexantur percita plagis, 

 Omne genus motus et coetus experiundo 

 Tandem deveniunt in talis disposituras, 



Qualibus haec rerum consistit summa creata. Lucr. i. 1021. 

 2 Nam qua cumque prius de parti corpora deesse 

 Constitues, hsec rebus erit pars janua leti : 

 Hac se turba foras dabit omnis material. Lucr. i. 1111. 



