In brief: For four reasons, and only one of them is Hegel’s fault. The content consists of concepts rather than representations. The sentences work differently from ordinary sentences. The texts were written for fellow specialists, not for beginners. And they remained unfinished.
1. The content: concepts instead of representations
Ordinarily one thinks in images, examples and feelings. Hearing the word „freedom“, one pictures a person casting off chains. Hegel’s philosophy demands something else: not to ask how freedom feels, but what its logical structure is. And it is not dealing with some remote object but with thinking itself — one is asked, so to speak, to think the water in which one swims as a thinker.
Hegel described this difficulty himself, and more precisely than most of his critics:
„[It] may be said in general that philosophy puts thoughts, categories, and more precisely concepts, in the place of representations. […] One side of what is called the unintelligibility of philosophy has to do with this. The difficulty lies partly in an inability — which in itself is merely unfamiliarity — to think abstractly, that is, to hold fast to pure thoughts and to move about in them. […] – The other part of the unintelligibility is the impatience of wanting to have before oneself in the manner of representation what is in consciousness only as thought and concept. […] it is as if consciousness had the ground removed from under it along with representation — the ground on which it otherwise has its firm and familiar footing. Finding itself transported into the pure region of concepts, [consciousness] does not know where in the world it is.“
Einleitung in die Enzyklopädie (in German)
The feeling that the ground has been removed is therefore not a failure on the reader’s part. It is an accurate perception of what is actually happening.
2. The sentence structure: the speculative proposition
The second reason concerns not the what but the how. An ordinary sentence is static: „The sky is blue.“ One takes in the information and moves on. A philosophical proposition in Hegel’s sense is not a container for information but the carrying out of a movement. When it is said that „being is nothing“, the understanding expects an assignment on the pattern A = B. What is required, however, is to think along with how being — taken purely and without any determination — turns into nothing.
Hegel analysed this too, in the Preface to the Phenomenology:
„Representational thinking, since its nature is to run on along accidents or predicates, […] is checked in its running on by the fact that what has the form of a predicate in the proposition is the substance itself. It suffers, so to put it, a counter-thrust. […] On this unaccustomed checking rest, for the most part, the complaints about the unintelligibility of philosophical writings […]. In what has been said we see the ground of the quite specific reproach so often made against them, that a good deal has to be read over and over again before it can be understood […]. The philosophical proposition, because it is a proposition, calls up the opinion of the ordinary relation of subject and predicate and of the customary bearing of knowing. This bearing, and the opinion of it, is destroyed by its philosophical content; opinion learns that what is meant is other than it supposed, and this correction of its opinion compels knowing to come back to the proposition and now to grasp it otherwise.“
Phenomenology of Spirit, Preface
This does not dispute the commonest complaint — that one has to read everything twice — but explains it, and declares it necessary. Returning to the sentence is no carelessness on the reader’s part; it is what the sentence demands of him: to grasp it as a process and not as a statement.
3. The addressee: written for fellow specialists
Hegel’s books are not introductions. They are a ruthless dialogue with the state of research of their time — and that state was extraordinarily high. They presuppose a reader who knows Kant, Fichte and Schelling as well as the author does. The argument is often conducted against them without their being named. Whoever does not know this context hears only one half of a conversation.
In that sense Hegel was, and is, a philosopher for philosophers — the back office, so to speak. This edition tries to supply the other half of the conversation: through the Remarks, the lecture transcripts, and the references to the opponents against whom a sentence was written.
4. The break: a death too early
Hegel died in Berlin in 1831, aged sixty-one, during a cholera epidemic, with a prior illness. Many clarifications and explanations that would have been needed he was no longer able to make. He had just begun the second edition of the Science of Logic; the whole second book remained as it stood in 1813. Much of what is available today by way of explanation comes not from him but from his hearers’ transcripts and from his editors’ Additions — with all the consequences that entails (see Is this sentence even Hegel’s?).
5. And finally
It is all right not to understand a sentence the first time. By Hegel’s own account it is in fact the normal case. Practical help: I understand every sentence, but not the thought and Do I have to have understood everything?