'Nature' in the Bible

For this reason God gave them up to vile lusts; for both their females changed the natural use into that contrary to nature;

For when those of the nations, which have no law, practise by nature the things of the law, these, having no law, are a law to themselves;

and uncircumcision by nature, fulfilling the law, judge thee, who, with letter and circumcision, art a law-transgressor?

For if thou hast been cut out of the olive tree wild by nature, and, contrary to nature, hast been grafted into the good olive tree, how much rather shall they, who are according to nature be grafted into their own olive tree?