If synonymy requires sameness of intension but intension is individuated by impossible-to-verify facts about reference across possible worlds, then synonymy exceeds any explanatory framework available to finite cognizers.

?Rate how convincing each reason is below to see the overall strength.

No one has weighed in yet. Be the first to share reasons for or against this statement.

Finite cognizers(epistemology and philosophy of mind): Thinking beings with limits on their knowledge and mental abilities—basically, beings like humans who can't know everything.
Reference (in philosophy of language)(what the translation manual must fix to make translation work): What a word or expression points to or stands for in the world—for example, the word 'dog' refers to actual dogs.
explanatory framework(Used to characterize the search for oncogenes in cancer research): Causal patterns, schemata, intuitions, hypotheses, evidential standards and various bits of evidence and data coming from different experimental settings and instrumental devices, which establish selective and local criteria of causal relevance that drive the search for, characterization and use of biological mechanisms.
intension(Contrasted with reference/extension as the semantic value assigned to expressions)

Based on where you are in your exploration