Perfect intervals are so-called because they were traditionally considered perfectly consonant, although in Western classical music the perfect fourth was sometimes regarded as a less than perfect consonance, when its function was contrapuntal.[vague] Conversely, minor, major, augmented or diminished intervals are typically considered less consonant, and were traditionally classified as mediocre consonances, imperfect consonances, or dissonances. Wikipedia, Perfect/Imperfect Intervals

Ramsay
"On December 24th, 1845, Mr. Ramsay announced to the people of Rothesay that he intended to open classes for the teaching of the science of music, commencing with the musical scale mathematically demonstrated as being the result of a System of vibrations which constitutes the basis of music, and accounts for every musical phenomenon of sound. Thus, by treating music in its origin, and viewing it not only in detached parts, but treating it as a whole, he would remove a multitude of unmeaning terms in common use, such as "imperfect" and "superfluous intervals," "discords," etc., etc., which tend to mystify and impede the learner's progress." [Scientific Basis and Build of Music, page 8]