Thoreau on the Impact of Thoughts

Thanks to Renee McGraw for posting this quote to the Core Parenting Group:

As a single footstep will not make a path on the earth, so a single thought will not make a pathway in the mind. To make a deep physical path, we walk again and again. To make a deep mental path, we must think over and over the kind of thoughts we wish to dominate our lives.

-Henry David Thoreau

An Official Source (I could not locate any reference to where Thoreau actually wrote it, so the text and the attribution are presumed to be accurate.)