Spinoza's notorious Tractaus Theologico-Politicus (TTP) has raised long controversy concerning the sincerity of the author. Some see a disguised atheism in it, and some a good will of adjusting to common Christians of the time. Are the “dogmas of the universal faith” Spinoza pretends to draw from the Bible a genuine proposal to liberate faith from superstition, or a cunning Pretext for ruining the spiritual authority? The present paper shows this question to be a false problem, by putting the issue into actual context of the time. The freedom of speech in the Republic of Holland was suffering crisis due to the lack of definition of “impiety”. The whole argument of theπP can be read as an attempt to determine the grammar of “piety and impiety” regulating the language game of the community: i.e. by whom, by what right and on what authority can a citizen rightly be condemned as “impious”. The dogmas in question are meant to be the objective demarcation of pious and impious faith