But this was not the direction which the Greek speculators took. On the contrary; as soon as they had introduced into their philosophy any abstract and general conceptions, they proceeded to scrutinize these by the internal light of the mind alone, without any longer looking abroad into the world of sense. They took for granted that philosophy must result from the relations of those notions which are involved in the common use of language, and they proceeded to seek their philosophical doctrines by studying such notions. They ought to have reformed and fixed their usual conceptions by Observation; they only analyzed and expanded them by Reflection: they ought to have sought by trial, among the Notions which passed through their minds, some one which admitted of exact application to Facts; they selected arbitrarily, and, consequently, erroneously, the Notions according to which Facts should be assembled and arranged: they ought to have collected clear Fundamental Ideas from the world of things by _inductive_ acts of thought; they only derived results by _Deduction_ from one or other of their familiar Conceptions.[12\1] [Note 12\1: The course by which the Sciences were formed, and which is here referred to as that which the Greeks did _not_ follow, is described in detail in the _Philosophy_, book xi., _Of the Construction of Science_.] When this false direction had been extensively adopted by the Greek philosophers, we may treat of it as the method of their _Schools_. Under that title we must give a further account of it. {63} CHAPTER II. THE GREEK SCHOOL PHILOSOPHY. _Sect._ 1.--_The general Foundation of the Greek School Philosophy._ THE physical philosophy of the Greek Schools was formed by looking at the material world through the medium of that common language which men employ to answer the common occasions of life; and by adopting, arbitrarily, as the grounds of comparison of facts, and of inference from them, notions more abstract and large than those with which men are practically familiar, but not less vague and obscure. Such a philosophy, however much it might be systematized, by classifying and analyzing the conceptions which it involves, could not overcome the vices of its fundamental principle. But before speaking of these defects, we must give some indications of its character.