The
/ði/
adverb
With a comparative or with more and a verb phrase, establishes a correlation with one or more other such comparatives.
“It looks weaker and weaker, the more I think about it.”
With a comparative, and often with for it, indicates a result more like said comparative. This can be negated with none. See none the.
“I'm much the wiser for having had a difficult time like that.”