—” But, What about ethics? What about existentialism?”—
Ethics (direct) and Morality (indirect) consists of nothing more than reciprocity. ( Productive, fully informed, warrantied, voluntary transfer independent of imposition of costs upon the investments of others by externality. ie:the continuous incremental expansion of tort).
And unethical and immoral action violates reciprocity (the same rule).
Or put more traditionally, the Silver Rule correctly defines ethics and morality. However, since the optimum game strategy is exhaustive investment (not boundless, but exhaustive) in opportunity for cooperation (thats the science), then the Golden Rule (which is secondary to the silver rule) increases the overall condition (productivity of cooperation).
As we innovate in both moral and immoral actions, we increase the suppression of immoral actions through the empirical discovery of them in conflicts (tort).
Unfortunately, law like norms, tends to lag, and lags more the more governments …. interfere…. with tort law (empirical) discovery and suppression of criminal, unethical, and immoral actions.
And worse, while norms usually make their way into legislation or command, (not necessarily tort), the effect of norms is increased by homogeneity and decreased by heterogeneity.
Moreover, group evolutionary strategy (moral and immoral both) sometimes requires or advances both ethical/moral, and unethical/immoral behavior, which results in norms that institutionalize unethical and immoral behavior. (Gypsies for example).
Anyway. Ethics and morality were an empirical not philosophical discovery. FIctionalisms to choose to invest in different strategies by which we create opportunities were the discovery.
Or said more simply: the primary challenge has been the christian one: the extensino of kinship love to non-kin (or at least near kin), but by personal rather than political means.
The principle issue with ethics and morality is that in the age of fiat currency we have substituted state insurance for interpersonal extensions, and in doing so eliminated the ability to test for exhaustion vs rent seeking. And the consequences are pretty obvious to the student of history.
I think the only questions left to philosophy are aesthetic (individual preferences) and strategies (group goods).
Science (Truth) is falsificationary (survival in the evolutionary markets for criticism). But anything that is not false, and not unethical/immoral is a candidate preferential, ethical, and moral good.
However, since time and resources are not infinite, we must rally one another around preferences, strategies, and goods. And while we may state them truthfully (operationally), or fictionally (allegorically), they are not matters of truth but of good or preference.
And this is, as far as I am able to determine, the role left to philosophy: choice. Truth is and has probably always been, the purvey of what we call ‘science’, or what I would call ‘testimony’.