The Overall Strategy

The overall strategy of Kant's moral theory is to derive the content of our obligations from the very concept of an obligation. Kant thought that we can figure out what we are obligated to do by analyzing the very idea of being obligated to do something. Where I am using the word ‘obligation,’ Kant used the German word Pflicht, which is usually translated into English as “duty.” In Kant's vocabulary, then, the strategy of his moral theory is to figure out what our duties are by analyzing what duty is.

A duty, to begin with, is a practical requirement – a requirement to do something or not to do something. But there are many practical requirements that aren't duties. If you want to read Kant in the original, you have to learn German: there's a practical requirement. Federal law requires you to make yourself available to serve on a jury: there's another practical requirement. But these two requirements have features that clearly distinguish them from moral obligations or duties.

The first requires you to learn German only if you want to read Kant in the original. This requirement is consequently escapable: you can gain exemption from it by giving up the relevant desire. Give up wanting to read Kant in the original and you can forget about this requirement, since it will no longer apply to you.