logical has 5 distinct synonyms spread across 3 of its 4 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is illogical.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
capable of or reflecting the capability for correct and valid reasoning
“a logical mind”
based on known statements or events or conditions
“rain was a logical expectation, given the time of year”
marked by an orderly, logical, and aesthetically consistent relation of parts
“a coherent argument”
Synonyms, antonyms and the broader and narrower relations for logical come from Princeton University’s WordNet. Full sources and licences.