The phrase "asserts what" is correct and usable in written English.
It can be used when discussing a statement or claim that is being made, particularly in academic or analytical contexts.
Example: "The author asserts what the implications of the study are for future research."
Alternatives: "claims that" or "states what".
"It asserts what the site is all about.
Monbiot vigorously asserts what the government should do to meet our energy and climate security needs.
Whether that means Mr. Xi will rein in the military or give it greater scope as China asserts what it calls its territorial rights in the South China Sea and East China Sea over the next decade will be one of the most important strategic questions facing the country as it enters its new leadership phase, they say.
A contradiction (antiphasis) is a pair of propositions one of which asserts what the other denies.
A false statement asserts what is not the case regarding the subject, by stating that the subject is other than it in fact is (263a-d).
But then conscience just asserts what self-interest dictates, and so the testimony of conscience is redundant and has no special authority.
First, it is worth considering whether one couldn't accept the idea, for reasons such as those outlined above, that in asserting that p one represents oneself as knowing that p, while taking the rule governing assertion to be, say, 'Do not assert what you take yourself not to know,' or some such.
Belief, acceptance, and assertion have a point: when we believe and assert, what we aim at is believing and asserting what is the case or, equivalently, the truth.
One asserted, "What were war crimes in 1945 is foreign policy in 2003".
Don't assert what is not yet established by the facts.
The protest was part of a series of demonstrations to assert what the opposition says is its constitutional right to demonstrate without permission from the authorities.
