What compels the assumption of an essential opposition of true and false, and would degrees of apparentness not suffice?

The passage

Nietzsche asks what compels us at all to assume an essential opposition of "true" and "false", and whether it does not suffice to assume degrees of apparentness and, as it were, lighter and darker shades and overall tones of semblance, different valeurs.

The last two sentences of the passage, both questions. The statement reports them as questions, »Nietzsche asks ...«, keeping »gleichsam« and the painters' »valeurs«, and does not turn them into the assertions a reader will hear in them, that nothing compels the opposition and that degrees suffice: the text asks, and a dispute may contest either the restraint or its opposite. »Stufen der Scheinbarkeit« is "degrees of apparentness" and »Gesammttöne des Scheins« "overall tones of semblance", the two words kept apart. The map sets the questions beside the division of the world into true and apparent that the fourth proposition of »Die ›Vernunft‹ in der Philosophie« 6 calls décadence (c-nietzsche-dividing-world-true-and-apparent-is-decadence), the questions offer what would stand in the division's place; the two texts are joined by no connective and the map sets no link. No Kant or Schopenhauer statement in the map asserts an essential opposition of true and false in these words, so no attack link is set; the comparison x-thing-in-itself sets the questions in its row on the division.