INDISTINCTNESS OF IDEAS. 187 



jeeble and irresolute a hand ; probably they cannot even prevent their 

 sliding back towards the obscurity from which they had been drawn, 

 or from being lost altogether. Such indistinctness and vacillation of 

 thought appear to have prevailed in the stationary period, and to be, 

 in fact, intimately connected with its stationary character. I shall 

 point out some indications of the intellectual peculiarity of which I 

 speak. 



1. Collections of Opinions. The fact, that mere Collections of the 

 opinions of physical philosophers came to hold a prominent place in 

 literature, already indicated a tendency to an indistinct and wandering- 

 apprehension of such opinions. I speak of such works as Plutarch's 

 five Books " on the Opinions of Philosophers," or the physical opinions 

 which Diogenes Laertius gives in his " Lives of the Philosophers." At 

 an earlier period still, books of this kind appear ; as for instance, a 

 large portion of Pliny's Natural History, a work which has very ap- 

 propriately been called the Encyclopoedia of Antiquity ; even Aristotle 

 himself is much in the habit of enumerating the opinions of those 

 who had preceded him. To present such statements as an important 

 part of physical philosophy, shows an erroneous and loose apprehen- 

 sion of its nature. For the only proof of which its doctrines admit, 

 is the possibility of applying the general theory to each particular 

 case ; the authority of great men, which in moral and practical mat- 

 ters may or must have its weight, is here of no force ; and the tech- 

 nical precision of ideas which the terms of a sound physical theory 

 usually demand, renders a mere statement of the doctrines very impei'- 

 fectly intelligible to readers familiar Avith common notions only. To 

 dwell upon such collections of opinions, therefore, both implies, and 

 produces, in writers and readers, an obscure and inadequate apprehen- 

 sion of the full meaning of the doctrines thus collected ; supposing there 

 be among them any which really possess such a clearness, solidity, 

 and reality, as to make them important in the history of science. Such 

 diversities of opinion convey no truth ; such a multiplicity of state- 

 ments of what has been said, in no degree teaches us what is / such 

 accumulations of indistinct notions, however vast and varied, do not 

 make up one distinct idea. On the contrary, the habit of dwelling 

 upon the verbal expressions of the views of other persons, and of being 

 content with such an apprehension of doctrines as a transient notice 

 can give us, is fatal to firm and clear thought : it indicates wavering 

 and feeble conceptions, which are inconsistent with sound physical 

 speculation. 



