Effective Altruism (E.A) appears the easiest Ethical Theory to shoot down since, for any theory of Justified True Belief (J.T.B) necessary for its implementation, every possible course of action can be proven to be consistent with E.A provided it holds at least one course of action to be unambiguously prescriptive at that particular point in time and space.
This is because, if an action is prescriptive, it must be the case that an associated set of compatible Theories of Justified True Belief has instrumental value. Thus it would be rational to devote scarce resources to promoting interest in and research into that set of J.T.Bs which are consistent with the E.A prescription we have posited as occurring.
However, since, in any prescriptive course of action, a sub-optimal variation in a single step can have greater imperative force than its optimal completion- for e.g. in saving a drowning child, we may not complete the step of combing its hair, so that when the T.V cameras arrive, it presents a more piteous aspect, thus giving greater imperative force to whatever E.A prescription we are urging- it therefore follows that either
1) Any course of action is consistent with E.A if it is merely a sub-routine.
2) All E.A sub-routines have the same property as its prescriptive 'courses of action'. For example, they must pass the test of protecting the life of another. Thus, no sub-routine could arise such that you let a child drown no matter how much attention and resources doing so might draw to the good cause.
The issue here is that a sorites type problem occurs in demarcating the last safe moment when a particular sub-routine becomes prescriptive.
If no such sorites problem arises then E.A can't be disambiguated from J.T.B. There is no supervenience or multiple realizability with respect to them. Either E.A is just a 'Turing Oracle' for J.T.B's halting problem or it is its own metalanguage and thus can't prove its own consistency or completeness- i.e. it can't show some of its propositions are prescriptive provided at least one isn't. In other words, it can exist, but only outside 'Public Reason' as an apophatic practice of a Mystic or Pietistic type.
This renders it bulletproof but silly.
In my next post I'll outline a method of saving E.A from silliness.
Edit- Well, I would have outlined such a method, for sure, but Waitrose has some real nice Rum marked down so fill your glass and take a shufti at this instead.