The existence of philosophical sin was a debate waged in the Catholic Church in the late seventeenth century.
A philosophical sin is a morally bad act which violates the natural order of reason, not the divine law.
The idea of philosophical sin, as opposed to theological sin, was advocated by those who wished to construct a moral system independent of God.
Those who believed in God and divine law yet contended for a distinction between philosophical and theological sin maintained that there are morally bad acts that, while violating the order of reason, are not offensive to God.
This doctrine of philosophical sin was censured as scandalous, temerarious, and erroneous by Pope Alexander VIII in 1690 in his condemnation of the following proposition: "Philosophical or moral sin is a human act not in agreement with rational nature and right reason; theological and mortal sin is a free transgression of the Divine law.