Answer and Explanation:
Scientific knowledge must always be focused on the search for facts and not essences, since they are the facts that manage to expose the functioning and composition of elements that are directly or indirectly interacting with human beings.
This is due to the fact that scientific knowledge is knowledge produced through tested and proven evidence, which is able to answer a question based on evidence, that is, the nature of scientific knowledge is the exposure of facts. Thus, we can affirm that, there is no scientific knowledge established in essences, because essences are subjunctive elements, impossible to be tested and proven.