Full Idea
A crucial idea for German Idealism (from Hamann) is that apparently passive receptivity and active spontaneity are in fact different degrees of the same 'activity, and the gap between subject and world can be closed.
Gist of Idea
Crucial to Idealism is the idea of continuity between receptivity and spontaneous judgement
Source
Andrew Bowie (German Philosophy: a very short introduction [2010], 3)
Book Reference
Bowie,Andrew: 'German Philosophy: very short intro' [OUP 2010], p.38
A Reaction
The 'passive' bit seems to be Hume's 'impressions', which are Kant's 'intuitions', which need 'spontaneous' interpretation to become experiences. Critics of Kant said this implied a dualism.
Related Idea
Idea 22057 Schelling sought a union between the productivities of nature and of the mind [Schelling, by Bowie]