'Instinct' in the Bible

For when Gentiles who have no Law obey by natural instinct the commands of the Law, they, without having a Law, are a Law to themselves;

For I do not understand my own actions [I am baffled and bewildered by them]. I do not practice what I want to do, but I am doing the very thing I hate [and yielding to my human nature, my worldliness—my sinful capacity].