Mastery Over Language

Mastery over language is only the illusion of rationality if there is not genuinely rationalistic thinking behind it, which is in turn only secured when thought is aligned with the necessary truths of logic.  Formal or unfamiliar words are no indicator in themselves that someone is rational.  Their espoused beliefs, as well as why they believe them (epistemology is of course part of belief, but it underpins the acceptance of truths themselves), are what determine if someone is rational.  As for the attainability of this, every person is already relying on the necessary truths of logic metaphysically and epistemologically, though they might not know this, and thus all a person has to do is give up assumptions and realize what they are already standing on.

It is far more important to know the laws of logic than it is to know the random vocal sounds or written symbols that people use to refer to things like scientific correlations, thoughts, and reason itself.  Words are at most in themselves a pragmatic means to the end of communication, as subjectively enamoring as they could be and as introspectively stimulating they can be--not because the construct of language is necessary to discover or understand logical truths or one's mental states, but because it can help people focus on things they already know (or could know if they tried).  While a rationalist can have both unrelenting rationality and adeptness with words, they do not hold the former because of the latter.

Not only can a person seem articulate without being rational on any level, but someone can be perfectly rational for years and years without being or becoming a master/mistress of language.  Verbal or written communication is a skill, and although there are linguistic incompetencies that someone might only repeatedly slip into without acknowledging their lack of skill because of irrationality, there is nothing about being a total rationalist for any amount of time that means one would develop linguistic talents.  Struggling with precision even as one does not use wrong words could last for a lifetime.  It still remains possible for mastery of language to be acquired over time with intentionality.

Even if a person starts from a point of communicative troubles, it is indeed logically possible to become incredibly precise with one's words in written or verbal form, both spontaneously and with forethought.  Should someone struggle with articulating what they know to be true by necessity because of reason, though, they have held to no error, shirked from no logical truth, and done nothing immoral.  Formal, precise words are hollow on their own.  Deep knowledge of and love of reason do not depend on linguistic familiarity or fluency.  When someone happens to feel like they are irrational because they have difficulty in communicating abstract necessary truths or lesser things, they can rest in the fact that their language skills are often irrelevant to the matter.