"Ptolemy, Dante, the two Bacons, and Boyle were even more to me than Darwin or Maxwell, as so much nearer the vanished van breaking into the dark of ignorance."
The sentence is from George MacDonald's Lilith. I don't quite understand the second half of the sentence. What's the metaphor here? Thanks!
EDIT: this already appears in the comment and I'm putting it here. From Google: van, the foremost part of a company of people moving or preparing to move forward, especially the foremost division of an advancing military force.
And by the way, I consulted my giant American Heritage Dictionary and didn't find this meaning. Is this chiefly a British usage?
Just my last question: I actually don't really understand what "as so much nearer" means. Could anyone explain it? Thanks so much!