by Daniel A. Kaufman
Both religion and philosophy endeavor to provide us with objective standards for our moral and aesthetic and other judgments, as well as our actions. Religion does it by stipulating a supreme authority in the person of God, while philosophy does it by appeal to reason and rationality, the authority of which is expressed by justifications or “warrants.” Some examples:
[A] A Christian tells you that he condemns same-sex romantic relationships. You say you’re fine with them. He says that you are wrong, and objectively so. On asking why, he tells you that God forbids same-sex romantic relationships and that God is the ultimate standard of right and wrong. He goes on to provide the appropriate scriptural and creedal evidence in support of his judgment.
[B] You are about to enjoy your shrimp scampi, and a philosopher tells you that it is wrong to eat it and that you should become a vegan. You tell her that you disagree, but as you prepare once again to tuck in, she tells you that you are wrong and objectively so. On asking why, she tells you that our ultimate obligation is to maximize happiness and minimize suffering, and your shrimp scampi is in violation of this. Unconvinced, you ask why you should accept this understanding of our ultimate obligation, and the philosopher tells you that rationality compels it and goes on to rehearse the reasoning step by step. (This example can be reconfigured to include any moral philosophy one wishes, as it will make no difference to the analysis.)
Now, both of these examples are explicitly about values, but this is incidental. After all, we could add:
[C] You’ve expressed sympathy with metaphysical anti-realism. A philosopher tells you that this is a mistake and that you should be a metaphysical realist instead. When you ask why, he explains that truth entails realism, and since you think your anti-realism is true, then you are really a realist. Unconvinced, you ask why you should accept this alleged relationship between truth and realism – or the account of truth presupposed in it – and the philosopher tells you that rationality compels it – that “it’s impossible to formulate any version of Anti-Realism that doesn’t immediately collapse into Realism” – and goes on to take you through his reasoning. 
In all of these cases something is invoked (God in one instance, rationality and reasons in another) that is supposed to provide an objective standard; something that commands you, rather than something you command. And the language is indicative of this ambition: “warranted”; “permissible”; “legitimate”; “justified”; all such talk connotes a scenario in which a person is authorized by some external authority to think or do something.
I’m afraid, however, that all of this is illusory or, as Anscombe put it with regard to the moral imperative: It has nothing more than “mesmeric” force. 
The issue is not that God’s existence and attributes are unverifiable and can only be stipulated (though this is a problem). Nor is it that different, equally qualified people may or may not find the same reasoning and appeals to rationality compelling, with no way to adjudicate amongst them other than by further appeals to rationality and reasoning (though this also is a problem, which I addressed in my most recent “Bits and Pieces”).  It also is not a matter of my examples involving disagreeing interlocutors trying to persuade one another, as I could easily develop examples that involve just one person considering competing positions and which would have identical implications.
Several years ago, I wrote about the force that written and uttered imperatives are alleged to have, and what I am going to say here is meant to supplement that analysis, not amend it.  The short of that piece was that the only imperatives that have any real force are the non-written, non-uttered ones: the imperative to go to the bathroom; the imperative to breathe; the imperative to digest food one has swallowed; and the like. But spoken and written imperatives? They only have force if the person to whom they are directed accepts them, and this remains true, even if these spoken or written imperatives are delivered under threat. One must care about the thing being threatened – or not care more about something overriding of it – for the threat to be of any good to the threatener in compelling the threatened.
This does not change, when we talk about standards that serve as a basis for imperatives. One may like to think that God or Rationality represents a standard, on the basis of which people are compelled to think or do some thing or other, but unless those people accept the standard, it does no such thing. The thing to notice, with regard to our current discussion, is that if they do accept it, that means that it satisfies their own standards.
A person cannot be compelled merely by way of written or uttered standards. If, after listening to the metaphysical realist, I agree that he is right and I should be a realist too, it’s because the standard he’s appealed to – in this case, “rationality” and whatever reasons he’s followed up with – is one that I accept, which means it satisfies my own standards. If, after listening to the Christian, I come to agree with him, it is because the standard he has presented – God and his commandments – is one that I embrace, again, according to my standards.
Part of the problem here involves conflations of the Manifest and Scientific Images and the illicit importing of concepts from one into the other. I can make – in the sense of ‘cause’ – your body move by shoving you, but I cannot “make” (in the same sense) you think something or act in a certain way by nothing more than an utterance or a scribble. That may only occur once I’ve interpreted and accepted the utterance or scribble, so some of our confusion in this area is mixed up with our more general tendency to conflate actions and events, which I’ve written about quite a bit. 
Believing and acting are among the chief modalities of agents, and the notion that one could be commanded or compelled by the mere contemplation of an utterance or bit of writing, without having first accepted it — on whatever basis one accepts and rejects things — is a very strange one. Indeed, our common practices in this regard suggest that we already know this, which is why we go to such lengths to come up with sanctions and penalties and rewards and reasons that people will care enough about or find suitably convincing (again, in light of whatever standards they operate under) that they will think or do the things we want them to.
That a standard cannot compel without first having been accepted according to the standards of the compelled person renders standards, both effectively and per se, subjective and (informally) paradoxical, because that which is accepted cannot be rightly characterized as compelled. I’m not sure the concept of a standard can be sustained without some element of compulsion in it, that class of things being what we call “recommendations.”
 G.E.M. Anscombe, “Modern Moral Philosophy” (1958), p. 6.