Complex sentence: After the Decembrist revolt, Idealist philosophy came into fashion, especially Hegel and Schelling, for their emphasis on the mind's creative potential and on systems constantly evolving towards an end goal.
Split into simpler sentences: After the Decembrist revolt, Idealist philosophy came into fashion, especially Hegel and Schelling. They liked its emphasis on the mind's creative potential and on how systems are constantly evolving towards an end goal.