I was reading the entry on moral particularism over at the Stanford Encyclopedia of Philosophy (my adviser is a particularist which is bad ’cause I’m generally a Kantian and he has been making me read Toulmin’s ‘the Place of Reason in Ethics’). So anyway, here is an argument that is presented as an argument for moral particularism,

Particularists suppose that this doctrine [about the variability of reasons] is true for reasons in general, so that its application to moral reasons is just part and parcel of a larger story. For an example that comes from a non-moral context, suppose that it currently seems to me that something before me is red. Normally, one might say, that is a reason (some reason, that is, not necessarily sufficient reason) for me to believe that there is something red before me. But in a case where I also believe that I have recently taken a drug that makes blue things look red and red things look blue, the appearance of a red-looking thing before me is reason for me to believe that there is a blue, not a red, thing before me. It is not as if it is some reason for me to believe that there is something red before me, but that as such a reason it is overwhelmed by contrary reasons. It is no longer any reason at all to believe that there is something red before me; indeed it is a reason for believing the opposite.

This strikes me as a very implausible claim.  First it isn’t clear what the ‘seems’ there is supposed to mean. Does it mean that I have a red phenomenal experience? Or is it that I have a phenomenal belief? If the former it then becomes odd to think of a red experience as a reason of any kind (especially if one is influenced by Sellers’ work)…but let us waive that. Is it really true that the appearence of a red-looking-thing is reason to believe that there is something blue out there? Well, only in light of my belief about the influence of the drug I am on. Buit then it sounds like we are doing exactly what is being denied here. The appearence of a red-looking thing before me is a reason to believe that there is something red out there UNLESS this reason is trumped by some other reason (like the belief in the example).

Given this very plausible interpretation of what is going on here the particularist cannot base his case on examples like this without further argument.