Some have claimed that matters of normativity, questions about what should be done, are the special province of philosophy. This is of course absurd, unless we want to claim that thinking about what is desired is the exclusive province of philosophy (since normativity can essentially boil down to that in many situations). Philosophy has no special techniques that give it access to truths that are closed off to other disciplines. Such thinking arises from assuming that philosophy is on the same level as the physical sciences, meaning that it has its own unique area of study that it is best suited to investigate. But such a model doesn’t even fit the physical sciences. Ultimately everything reduces to physics, and so by such reasoning it would appear that physics is the only real field of study. Physics, however, does not make the other sciences redundant. Rather, each science tackles the world in a more abstract way than physics, which allows it to better study certain phenomena. In fact all disciplines that intend to study the world can be put on a kind of scale, from the least to most abstract. On one end there is physics, and, slightly more abstract, chemistry. As we move towards the other end of the scale we encounter biology, psychology, economics, political science, and sociology. And finally, at the very far end, we have philosophy, the home of the most abstract approaches to the world. Some might deny that philosophy belongs on the scale, but I find it a hard claim to contradict. Certainly the sciences closer to the philosophy end of the scale (those that are more abstract), such as economics and political science, seem much more like philosophy than physics.
Because it is the most abstract, philosophy does not have a specific area of study or specific questions it tackles (except, shall we say, those too broad for a less abstract study, by default). Indeed philosophy is free to try to answer any question, as long as we keep in mind that sometimes the less abstract disciplines may be better suited to answering it, or that we may need to draw on them to reach a (correct) conclusion. But, while questions of normativity are not a special domain that philosophy is intrinsically suited to answer, they are often best tackled by philosophy, because often addressing them requires a broad range of considerations, and thus the problem is often too abstract to fit comfortably into the more specific disciplines.
Normative questions may seem unanswerable by other disciplines, then, because the non-philosopher is simply too “close” to one aspect of the situation. For example, an engineer can tell you all about the structural differences between a number of possible bridges, and the differences in cost. However when it comes to “what bridge should we build?” the engineer may not feel qualified to answer. After all, deciding which possibility is best depends on the expected use (sociology) as well as budgeting considerations (economics), and thus is at a loss to say what tradeoff between cost and safety would be endorsed by the voters who are ultimately funding the bridge (political science). While the engineer knows all the details about the engineering part of the problem they know a lot less about the other aspects of the problem. And hence won’t feel confident in knowing which bridge “should” be built. And the same can be claimed by specialists who study only some other aspect of the problem. But the philosopher isn’t concerned with any of the specifics to begin with, and is thus free to speculate about how these considerations fit together. And thus the philosopher may seem like the person who is to answer such normative questions. But really the engineer could have answered the question too, if they had been willing to consider the whole question from a more abstract standpoint.
This illusion, that only the philosopher is suited to answer questions concerning normativity, is also fostered by the way less abstract disciplines are pursued, namely with an almost exclusive focus on making predictions, without any thought to how those predictions are used. Or, in other words, less abstract disciplines are often pursued with the attitude that they are strictly descriptive. Now there is nothing intrinsically wrong with this, certainly that attitude leads to better theories about the objects of study. But it also promotes the idea that application of those theories is something to be handled by someone else. And since every discipline adopts this attitude then it seems that such questions can be settled by no one, except the philosopher. For example, when building the atomic bomb physics answered the question “can it be done?”. Economics answered the question “is it feasible to mass produce them?”. Military science answered the question “will they end the war?”. And political science/sociology answered the question “will the people generally approve?”. Of course plenty of people did question whether the bomb should be constructed (scientists included), but they didn’t see the question as lying within their professional capacity. And strictly speaking perhaps it didn’t. But there was nothing stopping from them from coming together and answering it definitively, except the idea that the answer was not reachable by consulting any specific field of expertise, and thus that putting them together wouldn’t be any better at getting results.
So, to return to my original point, maybe the philosopher often is the best person for answering such questions, not because they have special insights or methods, but because they are the most likely to take the whole picture in consideration, given that they don’t have a mastery over any of the specifics. But realizing that normativity falls to philosophy to answer because of its broad nature and not because of its intrinsic qualities removes some of the temptation to try to place philosophy in some special epistemic position, giving it the ability to answer questions without appealing to empirical fact.