Is it farther or further?
"to strive for," c.1400, from Old French aspirer "aspire to; inspire; breathe, breathe on" (12c.), from Latin aspirare "to breathe upon, to breathe," also, in transferred senses, "to be favorable to, assist; to climb up to, to endeavor to obtain, to reach to, to seek to reach; infuse," from ad- "to" (see ad-) + spirare "to breathe" (see spirit (n.)). The notion is of "panting with desire," or perhaps of rising smoke. Related: Aspired; aspiring.