Conditionality is a modal feature (in only the trivial sense, in the case of the material conditional). For φ to be conditioned on ψ is for the appearance of φ and ψ to be connected in some way over some region of modal space.
The knowledge account of assertion—roughly: one should not assert what one does not know—aspires to identify the norm distinctive of assertion. One main argument given in support of the knowledge account has been the success with which it explains a variety of Moore-paradoxical assertion. But that explanation does not generalize satisfactorily.
P. Grice and P. F. Strawson. 45. Philosophy and the Scientific Image of Man. (Wilfrid Sellars). 46. From The Blue and the Brown Books. (Ludwig Wittgenstein).