The preface to Hegel’s Phenomenology famously maintains that the conventional notion of a preface (e.g., “say what you are going to say”) is inapplicable to serious work in philosophy. There is an air of paradox about this, because in some sense he goes on to do what he just said was impossible. Hegel’s preface does summarize key conclusions of the book, but Hegel wants to make it clear that any such summary can at best be what Kant would call a dogmatic anticipation of real philosophical work yet to be done (in Brandom’s phrase, a “promissory note”).
I would note that this also reflects Hegel’s deep Aristotelianism. The way ideas are developed counts for much more than the way in which they are introduced. Aristotle did not follow the “say what you are going to say” model. Instead, he would begin with broad orienting remarks, a preliminary demarcation of subject matter, and a survey of common or leading views on the subject. Beginnings are the least certain part of a work; real substance emerges — if at all — from extensive development.
Of course it is possible to refer to an extensive development without producing or reproducing it in-line, but the relative soundness of such references depends on the soundness of the development and its applicability.
Simplicity is a pedagogical virtue that helps us on the uptake, but ultimately it cannot be the criterion of clarity. Real clarity comes from manifest interlinkages in a development that can be assessed independent of asserted conclusions (see Aristotelian Demonstration).
In his commentary, Harris says “The most important part here is Hegel’s insistence that the results of a science — whether it be philosophical or empirical — cannot be separated from the process (the Ausführung, or ‘execution’) by which they are reached” (Hegel’s Ladder I, p. 36). One of Hegel’s minor headings in the preface reads: “The principle is not the conclusion — against Formalism” (quoted on p. 48).
“We have a paradox here. The philosophical truth is absolute; but we have to hear it from one who is like ourselves. In this sphere, all particular situations are equally contingent. The philosopher, addressing her peers, will begin with this problem of how someone who accepts the finite human status can claim to say what is absolutely true — because that was precisely the problem that philosophy faced when the Phenomenology of Spirit was conceived. The philosopher and her peers, however, are not ‘in the midst of things’ in the way that the rest of us are. When she writes a book, she must take account of how we, the literate audience, are in medias res [in the midst of things]. Yet neither her situation nor ours is of any concern to philosophy as a systematic Science. For philosophy itself it is only the pure structure of ‘being in the midst of things’ that can be a possible starting point” (pp. 33-34).