He did not allow himself to be diverted
diverted= changed, in another direction
from his schemes
schemes= ideas, plans
by considerations
considerations= something thought about, a decision that you don't have to take but may want to.
of mercantile gain.
mercantile= things, possessions, money
He didn't want himself to think differently about his plans for a decision that may lead him to gain possessions, things, etc.
I hope this helps!
~kaikers