In reading the Edwards biography, I was reminded of this passage in Edwards' masterpiece Original Sin. He is speaking of what happened to human nature when Adam rebelled:
"The inferior principles of self-love and natural appetite, which were given only to serve, being alone, and left to themselves, of course became reigning principles; having no superior principles to regulate or control them, they became absolute masters of the heart. The immediate consequence of which was a fatal catastrophe, a turning of all things upside down, and the succession of a state of the most odious and dreadful confusion. Man did immediately set up himself, and the objects of his private affections and appetites, as supreme; and so they took the place of God. The inferior principles are like fire in an house; which, we say, is a good servant, but a bad master; very useful while kept in its place, but if left to take possession of the whole house, soon brings all to destruction." (Original Sin, Works of Jonathan Edwards vol. 3, pp. 382-83)
I find Edwards understanding of our "natural" desires helpful in recognizing the proper place for our "natural" desires. When contained in its proper sphere, fire has many important uses: heating a home, providing light, cooking food, etc. But the moment that fire escapes the fireplace and has free reign in the home, destruction is not far away. In the same manner, our natural desires for food, sex, love for self, love for family, etc., when not in total submission to the control of the Holy Spirit, lead to our own destruction.