Mesillas Yesharim 168

Chazal liken the neshama and guf to a lame person (neshama) and blind person (guf). The body houses the spirit. On its own, the body stagnates and falters along the path of life. The spirit is the driving force providing direction and focus. Together they are responsible for life decisions. Therefore, it is imperative that spirit and soul distinguish between right and wrong, choosing the proper path in life.

Provided courtesy of rabbisilber.com