Objeto y estructura del libro de Jensen

The journey from "is" to "ought" will follow four basic steps, corresponding to the four levels of reasoning. We will move step by step, beginning with purely speculative knowledge, moving to materially practical knowledge, then to virtually practical knowledge and finally to action. At the level of purely speculative knowledge we will look for a suitable object as a starting point. Taking a hint from Aquinas, we will examine natural inclinations. We will then determine how knowledge of natural inclinations might lead us to materially practical knowledge concerning the good. From there, we will move to virtually practical knowledge of how we ought to behave. Finally, we will examine how knowledge leads to action.