I do not know about Locke but Kant gives reasons why you should obey the social contract based on the fact that defends the natural law . For example the right to life as seen from a human stand point as in the right to Life , Liberty . etc the other natural law is Tooth and Claw kill or be killed we leave this behind when we enter society and become reason based creatures .This is where Nietzsche is wrong he allows you to do what ever you want . imagine a society were every one could steal or lie or even kill
Yep, we are molded by our environment! For Each the Right Environment