The story of this dark and evil assault enters the memory of man as one of his weapons in the struggle for the vindication of his essential humanity>
Last edited by philadelphia; 30-Oct-2008 at 10:52.
Break it down, starting at the end:
- man's (humankind's) 'essential humanity' is what makes people human.
- the "vindication" of that is the process of proving its worth (of justifying it)
- this process isn't easy (it's a "struggle") - and in a struggle one uses "weapons"
- "the memory of man" is humankind's recollection of what has happened over the last few thousand years (stored in the form of myths, stories, religious beliefs, 'common sense', cultural expectations and so on).
- what "enters this memory" (goes into this store) is "the story of this dark and vicious assault" (that is, something which - with any luck - was mentioned in the previous sentence or paragraph)
Because the reader can figure all this out only by unpicking it, starting at the end, it's very hard to work out what it means at a first reading (even for a native speaker).