PRIMARY CONCEPTS OF MODERN SCIENCE. 99 



it is sufficient for my purpose to have it conceded that in thought 

 properly so called, i. e., in those intellectual operations in which the 

 deliverances of sense are digested into that system of ideal forms and 

 relations which we call knowledge, or (what is the same thing) science, 

 we never deal with things as they exist, or are represented as existing, 

 objectively — that we have not, nor can we have, present to our minds 

 the whole complement of phenomena which are the constituents of a 

 material object, but always some one or more of them selected or 

 " abstracted " from the rest ; that being so, not only for the reason 

 that all our thought is, in the language of Leibnitz (adopted by Her- 

 bert Spencer in the first chapter of his " First Principles "), symbolical, 

 the attributes even of the simplest material object being too numerous 

 to be represented in consciousness at the same time, but for the far 

 weightier reason that our knowledge of the attributes of a material 

 object is never complete. I may say here, incidentally, that, in assert- 

 ing the abstract nature of thought, I am not taking sides in the inter- 

 minable controversy between Realism and Idealism, or Presentationism 

 and Representationism ; a controversy which would be speedily ended 

 if it came to be thoroughly understood that the phenomena of vision, 

 which, ever since the time of Plato, have furnished nearly all the meta- 

 phors for the description of intellectual operations, present but distant 

 analogies of the phenomena of perception, and that the puzzle about 

 mediate and immediate perception is but the common case of the ob- 

 scuration of a subject by a series of figures meant to illustrate it. In 

 my discussion, I am only generally concerned with the fundamental 

 relation which all our thought about objective reality bears to that 

 reality itself. 



There is, of course, no agreement among thinkers as to the nature 

 or even the number of successive steps which lead to the formation of 

 the elements of distinct thought. The terms most commonly employed 

 of late (by those, at least, whose authority commands the most respect, 

 viz., the comparative philologists, who are constrained, by the methods 

 of their own science, to treat psychological questions inductively), to 

 designate those steps, are Sensation, Perception, Representation, and 

 Conception. The first two of these I shall, for the moment, leave wholly 

 out of the account, as not relevant to the present inquiry, it being 

 admitted on all hands that the materials of distinct thought are either 

 representations or concepts. A representation may be generally de- 

 fined as an exhibition to the mind of the deliverances of sense (if the 

 object be real, or of the phantasy if the object be imaginary), in their 

 empirical order and form — in other words, as a mere mental image of 

 the object ; while, in the concept, these deliverances are reduced to 

 unity by the establishment of relations between them other than the 

 relation of their fortuitous concurrence, the concept, at the same time, 

 being made distinct by the establishment of relations between it and 

 the previous concepts of the mind. If I were writing a treatise on 



