STALLO'S "CONCEPTS OF MODERN PHYSICS." 97 



objects, therefore, are the smallest number requisite to constitute con- 

 sciousness. On the other hand, objects are conceived as identical by 

 an attention to their points of agreement ; though conception may also 

 be regarded as perception applied to a group of objects, so as to bring 

 before the mind its class characteristics ; the word well expressing 

 the gathering into one of the several qualities or properties by which 

 the group is distinguished from other groups. Conception is, there- 

 fore, the source of ideas, and the word concept expresses the union 

 effected in the mind of those attributes or properties under which a 

 given object is at any moment recognized. In other words, it is " the 

 complement of properties characteristic of a particular class." If the 

 class be a very special one the concept will apply to but few individu- 

 als ; but the complement of properties which it will connote will be 

 a very comprehensive one. If, on the other hand, the class be a very 

 wide or general one, the concept will apply to a much larger number 

 of individuals, but it will comprehend fewer attributes or properties. 

 As application widens, meaning narrows ; until from an infima species, 

 or in English a group of the most special kind, we rise to a summum 

 genus, or a class in which only such properties remain as are absolutely 

 essential to thought. The process by which this is done is the proc- 

 ess of abstraction, which consists in dismissing from consideration all 

 properties not essential to the particular class which we may wish to 

 form. Objects are known, it is further to be remarked, " only through 

 their relations to other objects," and each individual object only "as a 

 complex of such relations." No operation of thought, however, "in- 

 volves the entire complement of the known or knowable properties (or 

 relations) of a given object. In mechanics a body is considered sim- 

 ply as a mass of determinate weight or volume, without reference to 

 its other physical or chemical properties " ; and, in like manner, every 

 other department of knowledge only takes account of that aspect of 

 the object which it is necessary for the purpose in hand to study. 

 The mind can not completely represent to itself at any one time all 

 the properties or relations of an object ; nor is it necessary that it 

 should do so, as they can not possibly all be relevant to the same intel- 

 lectual operation. Our thoughts of things are thus symbolical, because 

 what is present to the mind at a given moment is not the object in the 

 totality of its relations, but a symbol framed for the occasion, and em- 

 bracing just those relations under which the object is to be considered. 

 A concept in which all the relations of an object should be embraced 

 is an obvious impossibility. We can not stand all round a thing all at 

 once ;'we must choose our side, or, in other words, fix upon our point 

 of view. 



The above line of thought will be familiar to all students of phi- 

 losophy, and particularly to those acquainted with the writings of Mr. 

 Herbert Spencer. For some reason or other, however, Mr. Stallo 

 abstains, not only here but generally throughout his book, from any 



VOL. XXI. *7 



