Science is the systematic classification of experience.
— George Henry Lewes

By the definition accepted in the United States, any person with even a small amount of Negro Blood... is a Negro. Logically, it would be exactly as justifiable to say that any person with even a small amount of white blood is white. Why do they say one rather than the other? Because the former classification suits the convenience of those making the classification. Society, in short, regards as true those systems that produce the desired results. Science seeks only the most generally useful systems of classification; these it regards for the time being, until more useful classifications are invented, as true.
S. I. Hayakawa classification quote

Language is legislation, speech is its code. We do not see the power which is in speech because we forget that all speech is a classification, and that all classifications are oppressive.
— Roland Barthes

Human beings, for all their pretensions, have a remarkable propensity for lending themselves to classification somewhere within neatly labeled categories. Even the outrageous exceptions may be classified as outrageous exceptions!
— W.J. Reichmann

You ask what is the use of classification, arrangement, systemization? I answer you: order and simplification are the first steps toward the mastery of a subject-the actual enemy is the unknown.
— classification quotation by Thomas Mann