If dialectics is merely a form of thinking, wouldn’t this subordinate nature or at least the laws of nature to idealism? Engels is returning to a pre-Hegelian (Kantian) distinction between form and content, and thus places the content beyond our reach.
Engels’ conception of dialectics is so warped that he explicitly calls nature dialectical and not metaphysical: ‘Nature is the test of dialectics […] and thus has shown that in the last resort nature works dialectically and not metaphysically.’
— Engels, Anti-Dühring.
‘This dialectic is not an activity of subjective thinking applied to some matter externally, but is rather the matter’s very soul putting forth its branches and fruit organically.’
— Hegel, Outlines of the Philosophy of Right (tr. Knox), §31.
From Hegel’s Lectures on the Philosophy of Religion (trans. Spiers)
‘Philosophy is not a wisdom of the world, but a wisdom of what is not of the world’ p.19
To sum up, the Idea is the self-conscious Notion, or the Notion that comprehends itself. This is why the ‘Philosophy of Right’ is concerned with ‘Idee’ rather than ‘Begriff’, because we are not dealing with 'dead' 'material objects' but elements of our self-conscious life.
‘Notion’ versus ‘Idea’ in Hegel [Thread]
What Hegel calls ‘Begriff’ Miller translates as 'Notion' and Knox translates as 'Concept'. Whichever translation we adopt, the ‘Begriff’ is something comprehended as a unity of its essence (‘Wesen’) and its determination (‘Bestimmung’).
‘The Greeks and Romans were satisfied with gods so poorly equipped because they had the eternal and self-subsistent within their own hearts.’
Hegel, ‘Early Theological Writings’, 157.
From Hegel's 'Political Writings':
'Only the future can tell how dreary and spiritless life will be in a modern state [...] in which everything is regulated from above, and where nothing of universal significance is entrusted to the [people]'.