Antonyms of adj sophistic

1 of 2 senses of sophistic

Sense 2
sophistic, sophistical -- (plausible but misleading)

INDIRECT (VIA invalid) -> valid -- (well grounded in logic or truth or having legal force; "a valid inference"; "a valid argument"; "a valid contract")

Similarity of adj sophistic

2 senses of sophistic

Sense 1
sophistic -- (of or pertaining to sophists)

Sense 2
sophistic, sophistical -- (plausible but misleading)
       => invalid (vs. valid) -- (having no cogency or legal force; "invalid reasoning"; "an invalid driver's license")