@Dosed,
well this book is one of those that forever changed the course of philosophy, as I understand it, by being so very abstruse that it caused a major reaction against metaphysics and the whole 'grand tradition' in Western philosophy.
One of the other contributors here recommends an author called Kojeve on Hegel, he is one of the better interpreters. There is a pretty decent preview on Google Books.
I will hazard a very uninformed speculation on Hegel. Be warned I am not knowledgable in him. His major idea is the absolute consciousness, or Spirit, manifesting through various historical phases, which are the subject of his great insight into 'the historical dialectic' of thesis antithesis and synthesis. Not many other thinkers in the West ever understood the idea of the Spirit in the way that he has. It is much closer to some modern Indian philosophers, particularly Aurobindo, than anything since in Western philosophy.
This idea of 'formal truth' - be aware of the use of this term - it is connected to 'the laws of form' in the the platonic notion of form, not in the sense of 'a formality'. The reason they are 'inseperable' in this way of thinking goes back to the idea of 'universals'. These are held to be the categories which structure the universe. This way of thinking was native to Aristotlean Scholasticism, but was rejected by the Nominalists, starting with William of Ockham. The realists in the Platonic tradition says that Universals, or Forms, are real and that phenomena are only real insofar as they embody these forms. The Nominalists rejected the whole idea of forms and universals, and said that only individual things are real. The modern world is overwhelmingly nominalist in its orientation, and the laws of form have (you could argue) morphed into the notion of scientific law.
But I am improvising here, I have never wrestled with this book, I will leave further comment to someone who has.