logical

log-i-cal

adjective

Following the rules of logic or sound reasoning; sensible and coherent.

"Her argument was very logical and easy to follow."

Thesaurus

Synonyms: formal, discursive, ratiocinative, dianoetic, legitimate, valid, lucid, rational, coherent, consistent, seamless, ordered

Antonyms: illogical, incoherent, unlogical