This use of φύσις as referring to a "natural order" in "Romans 1:26" and "1 Corinthians 11:14" may have been influenced by Stoicism. The Greek philosophers, including Aristotle and the Stoics are credited with distinguishing between man-made laws and a natural law of universal validity, but Gerhard Kittel states that the Stoic philosophers were not able to combine the concepts of νόμος (law) and φύσις (nature) to produce the concept of "natural law" in the sense that was made possible by Judeo-Christian theology.