> In discussions such as this I like to use the analogy of Newton's Laws of Motion which after hundreds of years still work well for 'everyday' use but they're all but useless in other endeavors such as our phones' GPS - to get there we had to progress through Lagrangian and Hamiltonian mechanics to Relativity over several hundred years. The same applies to philosophy and philosophical argument and it's why I find it so interesting.

This is where I don't agree. Philosophy and physics are very different.

In physics, at some point certain major theories become established and universally accepted. Pretty much all physicists accept Einstein's theories of relativity as correct–up to the limits of our current ability to test them.

By contrast, in philosophy, professional consensus is vastly more elusive than in physics. The same debates rage from generation and generation, without ever coming to any clear resolution. This is especially true when it comes to highly controversial areas such as ethics:

Are moral statements cognitive or non-cognitive? If cognitive, is their truth objective or subjective? If objective, is the ground of their objectivity natural, non-natural, or supernatural? And, if their truth is objective, which proposed normative ethical theory best approximates that truth: Utilitarianism? (Act, rule or preference?) Deontology? Virtue ethics? Natural law theory? Some combination of two or more of them? Something else entirely?

Philosophy, as a field, is nowhere near reaching consensus on those questions, and consensus seems just as far away now as it did a century ago, and will probably seem just as distant a century from now.

That's not to say no issues ever get resolved. The IEP reports [0] that "...philosophers seem to have reached a consensus... that indirect doxastic voluntarism is true" – and I have no reason to doubt its report. But indirect doxastic voluntarism (that we have some measure of indirect voluntary control over what we believe) is not an especially interesting doctrine. The far more interesting question of direct doxastic voluntarism (whether, at least in some cases, we have the ability to make a direct voluntary choice of what to believe) – is as disputed as it ever was.

Another example of a resolved issue – during the 1950s and early 1960s, logical positivism was enormously popular in (Anglophone) academic philosophy. However, consensus was soon reached that, at least in its classical "meaningfulness is verifiability" formulation, it is a self-refuting position – by the 1970s, essentially everyone had moved on from it, and that consensus has endured from then until now. So, at least occasionally, professional consensus can emerge either that (a) some minor theory is true, or (b) some major theory is false. But consensus on the truth of major theories seems to perennially escape us – quite unlike the case of physics.

> rather it's the milieu in which they're now operating which is seemingly putting strictures on what they do. Like fashion, a set of cultural boundary conditions is determining what they actually do in practice. (BTW, I accept with Academia in the horrible state it's currently in at present that challenge is more than unusually difficult.)

One philosopher might be a moral anti-realist, who believes that morality is simply a subjective expression of emotional attitudes. Another may be a moral realist, yet be convinced that morality can be objectively defined in terms of some theory of the natural sciences (such as evolutionary psychology). A third may be a divine command theorist, convinced that morality can be objectively defined as obeying God's will (as revealed in the Bible or Quran or whatever). All three have reasons to reject Moore's positions, but those reasons are rather different in each case. So the fact that Moore's position is widely disputed, is not a sign of "groupthink". (For what it's worth, I personally think Moore is mostly right–but I know there are many philosophers who disagree.)

> There's more than a hint of postmodernism in your response.

I don't agree. I don't have much sympathy for postmodernism – which is itself somewhat of a vague term, but it is generally associated either with doubt about the existence of objective truth, or else the claim that we are fundamentally unable to know what it is even if it does exist. Whereas, contra postmodernism, I am quite convinced that objective truth exists, and that we do not have any fundamental disability in knowing it – even in philosophy.

My motivation was simply that, if someone says "discipline X says Y", that can be reasonably taken as saying "discipline X has a professional consensus that Y"–which I know in this case to be false. If you had couched your point, not in terms of unqualified "philosophy", but simply as being one philosophical theory, or philosophical school, or individual philosopher (Moore) – I probably would not have replied.

[0] https://iep.utm.edu/doxastic-voluntarism/