  We outline an intuitionistic view of knowledge which maintains the original
Brou\-wer-Heyting-Kolmogorov semantics for intuitionism and is consistent with
the well-known approach that intuitionistic knowledge be regarded as the result
of verification. We argue that on this view co-reflection $A \rightarrow
{\bf{K}} A$ is valid and the factivity of knowledge holds in the form ${\bf{K}}
A \rightarrow \neg\neg A$ `known propositions cannot be false'.
  We show that the traditional form of factivity ${\bf{K}} A \rightarrow A$ is
a distinctly classical principle which, like {\it tertium non datur} $A\vee\neg
A$, does not hold intuitionistically, but, along with the whole of classical
epistemic logic, is intuitionistically valid in its double negation form
$\neg\neg({\bf{K}} A\rightarrow A)$.
  Within the intuitionistic epistemic framework the knowability paradox is
resolved in a constructive manner. We argue that this paradox is the result of
an unwarranted classical reading of constructive principles and as such does
not have the consequences for constructive foundations traditionally attributed
it.
