Ladd, G. T. (1894). Feeling: Its nature and classes. In G. T. Ladd, Psychology: Descriptive and explanatory: A treatise of the phenomena, laws, and development of human mental life (pp. 162-187). New York, NY, : Charles Scribner's Sons.
http://dx.doi.org/10.1037/12930-009
The phenomena observed by attending to that aspect of consciousness which is known by the name of "Feeling" have baffled the student of psychology from the beginning of investigation to the present time. The reasons for this fact are, chiefly, the following three: First, the amount of analysis devoted to this aspect of mental life has been too small, whether we regard its relation to the intrinsic difficulty of the subject or to the amount of study bestowed upon other aspects. Then, too, the connection of affective phenomena with hotly debated questions in ethics, aesthetics, and religion may have contributed to increase the influence of prejudice in the study of these phenomena. But, second, the nature of language and of the relation it sustains to the description and explanation of psychoses is such as relatively to hinder the growth of a science of the human feelings. Language is framed, primarily, to convey an accurate knowledge of those objects in whose existence and relation to man his most fundamental as well as most highly intellectual needs make him interested. But language describes and explains the feelings of man only in a secondary, inaccurate, and always figurative way. But the third and chief reason for the unsatisfactory state of the psychology of feeling is the very nature, conditions, and laws of the phenomena of feeling itself. As to its nature, feeling is relatively indescribable. (PsycINFO Database Record (c) 2016 APA, all rights reserved)