Koerner has written a philosophical masterpiece in the form of an art book. Caspar David Friedrich is one of the most complex and thought-provoking of nineteenth-century artists, whose whose exploration of perception shows up in his most mundane paintings as well as his most grandiose.
Koerner shows us how even a painting of something as simple as a bushy thicket in the snow contains many subtle contradictions and complexities that baffle the eye as we examine it more closely. The apparent simplicity and underlying intensity of many of his works is similar to that of Edward Hopper, on whom he seems to have been a major influence (and this book bears comparison with Kranzfelder's "Hopper").
Friedrich specialized in painting the human figure seen from behind (rueckenfigur), and this ties in with sense of nostalgia that is a major component of his art. A really notable example of this is "Abbey Graveyard under Snow", a painting of a ruined mediaeval monastery with a spectral procession of monks from a bygone age; this painting was destroyed by bombing in 1945 and exists only in reproduction - a ghostly painting of ghosts.
Koerner's dense prose is heavy going, but well worth the effort because it contains so much; the author evidently has a thorough grounding in philosophy as well as a great sympathy for his subject.
The last chapter is entitled "deja vu", and this sums up one of the main feelings aroused by this art. The last sentence is worth quoting:
"And it arrests you on the Dresden heath, before the thicket in winter, when what you thought were just alders in the snow are fragments of your darkest history".

Joseph Leo Koerner must rank as one of the most able and compelling figures writing in the field of Art History today. As with his previous work on Caspar David Friedrich this work is a masterpiece of interpretative criticism and research. Koerner proceeds always from close readings of individual works, but then sets them at the centre of a nexus of complex philosophical and socio historical questions. He invokes not only the writings of Durer's contemporaries, but such figures as Foucault and Adorno in drawing out the profoundest implications from the works cited. If proof were neeeded that art history can be urgent and disturbing rather than pedantic and arcane, then this book should offer it. As one reaches the end of this book one understands that the complex issues of identity which Durer and his circle grappled with are as vital and disturbing at the turn of the millenium as the were when Durer worked on the brink of the half millenium.