What’s the difference between classic and classical? Both words, befitting their roots in the word class, refer to quality, but the meanings are distinct.
Classic and classical, both first attested around the turn of the seventeenth century, derive from the French term classique, a descendant of the Latin word classicus, which (in turn stemming from classis) denoted the first rank of Roman citizens.
Classic means “of recognized value,” or “enduring” or “traditional”; the sense is of something that represents a standard of excellence or has a timeless quality. It may also be used to refer to something authentic or typical; in the latter sense, it is sometimes used colloquially to refer to a memorable incident or quote—often an unfortunate one (“Remember when Joe stumbled into John and Mary’s wedding cake? That was classic!”). Alternatively, it may apply to something of historical or literary significance (as in reference to a classic rivalry between two historical figures).
As a noun, it denotes a traditional event or something with a longstanding reputation of high quality. As such, it is often applied to sports events such as the CBS Sports Classic, an annual college-basketball extravaganza. In plural form, it refers to the study of ancient Greek and Roman culture, language, and literature; note that this term is not capitalized.
Classical also means “traditional,” but the sense is more of something authoritative rather than authentic: A scholar of the classics is a classical scholar, not a classic scholar, and a liberal arts curriculum (presumably) results in a classical education, not a classic education. (Likewise, a reference to Greek or Roman civilization in its heyday will describe the place as “classical Greece” or “classical Rome.”) The word’s perhaps most frequent application is in the phrase “classical music,” which refers to compositions for symphonies or chamber-music ensembles in a European-based tradition as distinct from more vernacular forms such as folk music or jazz.
One functional distinction between the two words is that although classic can be a noun or an adjective, classical is never used as a noun.
This has been a problem for me, not so much with classic vs classical but in the medical field, like neurologic vs neurological, pathologic vs pathological, radiologic vs radiological…I tend to leave off the -al because I don’t see that it adds anything except extra letters, or that it makes a difference in meaning, even nuance. Is it a neurologic exam or a neurological exam? I am not sure if there is a difference and if so, when to use which.