This paper discusses the philosophy of St. Thomas Aquinas concerning man's will. Essentially or by nature, what man wills is good, since he can only will something to which he is inclined, and "every inclination is to something good." (Aquinas 2002) But every inclination takes a form, whether natural or apprehended. The form that exists in the nature of things appeals to the natural appetite, while that apprehended or perceived form appeals to the sensitive, or the rational or intellective appetite. In layman's terms, a person can only will something, which he perceives to be or do him good, but that idea of what is good can be entirely subjective and altogether incorrect or even evil.