220 ROMAN PHILOSOPHY. 



of our senses. Of their fallibility, however, we may easily assure 

 ourselves ; for in cases in which they are detected contradicting each 

 other, all cannot be correct reporters of the object with which they 

 profess to acquaint us. Food, which is the same as far as sight and 

 touch are concerned, tastes differently to different individuals; fire, 

 which is the same to the eye, communicates a sensation of pain at one 

 time, of pleasure at another ; the oar appears crooked in the water, 

 while the touch assures us it is as straight as before it was immersed. 1 

 Again, in dreams, in intoxication, in madness, impressions are made 

 upon the mind, vivid enough to incite to reflection and action, yet 

 utterly at variance with those produced by the same objects when we 

 are awake, or sober, or in possession of our reason. 2 



It appears then that we cannot prove that our senses are ever 

 faithful ; but we do know they often produce erroneous impressions. 

 Here then is room for endless doubt ; for why may they not deceive 

 us in cases in which we cannot detect the deception ? It is certain 

 they often act irregularly ; is there any consistency at all in their 

 operations, any law to which these varieties may be referred ? 



It is undeniable that an object often varies in the impression which 

 it makes upon the mind, while, on the other hand, the same impression 

 may arise from different objects. What limit is to be assigned to 

 this disorder ? is there any sensation strong enough to assure us of 

 the presence of the object which it seems to intimate, any such as to 

 preclude the possibility of deception ? If, when we look into a 

 mirror, our minds are impressed with the appearance of unreal trees, 

 fields, and houses, how can we ascertain whether the scene we directly 

 look upon has any more substantial existence than the former? 3 



From these reasonings the Academics taught that nothing was certain, 



1 " Tu autem te negas infracto remo neque columbse collo commoveri. Primum 

 cur ? nam et in remo sentio non esse id quod videatur, et in columba 1 plures videri 

 colores, nee esse plus uno, &c." (Lucullus, 25.) [" You say that you are unin- 

 fluenced by the instances of the broken oar and the pigeon's neck. First, let me ask 

 you why ? for, in the case of the oar, I perceive that what appears is not ; and, in 

 the pigeon, that many colours are apparent, when there is but one, &c." Editor.^ 



2 Lucullus, 1618, 2628. 



3 " Scriptum est : ita Academicis placere, esse rerum ejusmodi dissimilitudines ut 

 alise probabiles videantur, aline contra ; id autem non esse satis cur alia percipi posse 

 dicas, alia non posse ; propterea qu6d multa falsa probabilia sint, nihil autem falsi 

 perceptum et cognitum possit esse. Itaque ait vehementer errare eos qui dicant ab 

 Academic sensus eripi, a quibus nunquam dictum sit aut colorem aut saporem aut 

 sonum nullum esse ; illud sit disputatum, non inesse in his propriam, qua? nusquam 

 alibi esset, veri et certi notam. (Lucullus, 32.) [" It has been written thus : 

 The Academics hold that there is in things that dissimilarity, that some appear pro- 

 bable, others the contrary; but that this is no sufficient reason for saying that some 

 may be comprehended, others not ; because many false impressions are probable, but 

 no false impression can be the object of comprehension and knowledge. He affirms, 

 therefore, that those are greatly mistaken who say that the Academics take away the 

 existence of the senses ; inasmuch as they have never denied that there are such 

 things as colour, taste, and sound ; but they contend that there is not in these things 

 a peculiar mark of reality and certainty, not existing elsewhere." Editor."] See 

 also 13, 24, 31 ; de Nat. Deor. i. 5. 



