When the necessity operator $\square$ of modal logic is read as an epistemic knowledge operator, describes the ensuing reading of the $\text{T}$ axiom scheme:

• • $\square \phi \to \phi$

where $\to$ is a binary conditional connective. The epistemic reading is then:

• • if $\alpha$ knows that $\phi$, then $\phi$ is true

i.e., that knowledge of a proposition requires the truth of that proposition.