100 INTRODUCTION 



several occasions Leibniz uses the rainbow as a simile by 

 which to illustrate what he means by a phenomenon bene 

 fundatum 1 . He simply mentions it without explanation; 

 but we may suppose him to have meant that the rainbow 

 is the type of a phenomenon bene fundatum, inasmuch as. 

 being merely colour, it exists as a rainbow only for those 

 who actually behold it, and is thus a mere appearance, 

 while, being an appearance which results from certain 

 physical conditions of light and moisture, it has a ground 

 or cause, it is the phenomenon of something and is there- 

 fore bene fundatum and not a pure phantasm or illusion. 



Thus, in general, the qualities of matter, whether 

 secondary, as colour, smell, sound, &c., or primary, as 

 extension, figure, and motion, are phenomena bene fundata. 

 Taken by themselves, as qualities of a matter which has 

 no 'soul,' they are not real but merely subjective. But 

 their order or connexion implies a principle of order (i. e. 

 a soul), and accordingly they are confused (i. e. not fully 

 analyzed) representations, perceptions, or symbols of 

 that which, expressed distinctly, is real substance. 

 Ultimately ( ' metaphysically ' as Leibniz would say) they 

 are reducible to non-spatial perceptions or appetitions of 

 Monads ; but in the form in which they are given to us 



outside of us is verified by means of truths of reason ; as the pheno- 

 mena of optics are explained by geometry. Yet it must be 

 admitted that this certitude is not of the highest degree. . . . For it 

 is not impossible, metaphysically speaking, that there is a consecu- 

 tive dream lasting as long as the life of a man ; but that is a thing 

 as contrary to reason as would be the fiction that a book could 

 be formed by chance through throwing down type in confusion.' 

 Cf. Locke, Essay, bk. iv. ch. 2, 14 ; Eraser's ed., vol. ii. pp. 185 

 sqq., with Prof. Eraser's Notes, and also his Notes on pp. 332 and 333. 

 1 Cf. Epistola ad Des Bosses (,1715) (E. 728 b ; G. ii. 504) : * I prefer 

 to say that not substances but species' [i.e. sense -qualities] 

 'remain, and that these are not illusory, like a dream or like 

 a sword pointing towards us out of a concave mirror, or as 

 Dr. Faustus ate a cartful of hay, but true phenomena, that is, in 

 the sense in which a rainbow or a mock sun is a species, indeed 

 as, according to the Cartesians and in truth, colours are species.' 

 Also Epistola ad De Voider (1706) (G. ii. 281, note) : * Extension itself, 

 mass and motion, are no more things than the image in a mirror 

 or the rainbow in a cloud. . . .They exist vo^y rather than <pvo-(i, to 

 use the expression of Democritus ' (p. 282, note). 



