The ethical orders are the essence of the individual. But the individual can also set himself apart from them. He has his own wishes and whims. That is why the orders meet him as duties. They bind his will.

Where can I find out what my duties are?

In morality we found no answer to this. Mere duty was empty. Now it is different. The duties arise from the orders in which we live: from the family, from society, from the state.

So the whole third part is a doctrine of duties. We just do not add after every step: So this is your duty. It is enough to show which relations are necessary. The duty follows from this by itself.

Summary: For the individual, the ethical orders are binding duties. Family, society and state show what these duties are. The third part develops them one after another.