I did a detailed analysis earlier, I am posting this as an exception.
FDP claimed he understood Boyd's point based on merely a cherry picked para from below, but he is wrong.
Below is my detailed analysis to justify why FDP [as a moral skeptic] has a moral cognitive moral deficit in Morality.
S4.7 How To Be A Moral Realist
Richard Boyd
There remains but one of the challenges to Moral Realism which we are here considering.
Objection: Moral Realism is Impossible – no relation between moral facts and action
It has often been objected against Moral Realism that there is some sort of logical connection between moral judgments and reasons for action which a moral realist cannot account for.
Objection to Moral Realism:
Moral judgments are seen as inherently connected to reasons for action.
Since facts (like moral facts in moral realism) don't provide reasons for action,
moral realism must be false.
It might be held, for example, that
the recognition that one course of action is morally preferable to another necessarily provides a reason (even if not a decisive one) to prefer the morally better course of action.
Mere facts (especially mere natural facts) cannot have this sort of logical connection to rational choice or reasons for action.
Therefore, so the objection goes, there cannot be moral facts;
Moral Realism (or at least naturalistic Moral Realism) is impossible.
Naturalistic Moral Realist must deny moral judgments necessarily provide reasons for action; possible for humans where moral judgments provided no reasons for action.
It is of course true that the naturalistic moral realist must deny that moral judgments necessarily provide reasons for action; surely, for example, there could be nonhuman cognizing systems which could understand the natural facts about Moral goodness but be entirely indifferent to them in choosing how to act.
Moral judgments might provide for them [nonhuman cognizing systems] no reasons for action whatsoever.
Moreover, it is hard to see how the naturalistic moral realist can escape the conclusion that it would be logically possible for there to be a human being for whom moral judgments provided no reasons for action.
The moral realist must therefore deny that the connection between morality and reasons for action is so strong as the objection we are considering maintains.
The appearance of an especially intimate connection must be explained in some other way.
Naturist response: preference one choice among two is morally preferable, indicate some moral reason exists
The standard naturalist response is to explain the apparent intimacy of the connection by arguing that the natural property Moral goodness is one such that for psychologically normal humans, the fact that one of two choices is morally preferable will in fact provide some reason for preferring it.
Homeostatic consequentialist conception of the Good re human needs, explain connection between moral judgments and reason for action; but do not explain why it is a necessary one
The Homeostatic consequentialist conception of the Good is especially well suited to this response since it defines the Good in terms of the homeostatic unity of fundamental human needs.
It seems to me that this explanation of the close connection between moral judgments and reasons for action is basically right,
but it ignores—it seems to me—one important source of the anti-realist’s intuition that the connection between moral judgments and rational choice must be a necessary one.
Moral Judgments are motivationally indifferent due to cognitive deficit. Anti-realists argue this deficit due to no necessary connection.
What I have in mind is the very strong intuition which many philosophers share
that the person for whom moral judgments are motivationally indifferent would not only be psychologically atypical [not representative of a type, group, or class.] but would have some sort of cognitive deficit with respect to moral reasoning as well.
The anti-realist diagnoses this [cognitive] deficit as a failure to recognize a definitional or otherwise necessary connection between Moral goodness and reasons for action.
Boyd differed from the anti-realist’s view of no necessary connection; instead to Boyd argued it is akin to a perceptual deficit
I think that there is a deep insight in the view that
people for whom questions of Moral goodness are irrelevant to how they would choose to act - suffer a cognitive deficit.
I propose that the deficit is not—as the anti-realist would have it—a failure to recognize a necessary connection between moral judgments and reasons for action.
Instead, I suggest, if we adopt a naturalistic conception of moral knowledge we can diagnose in such people a deficit in the capacity to make moral judgments somewhat akin to a perceptual deficit.
The perceptual deficit is in terms of Hume’s Causal Theory of moral knowledge to moral reasoning re empathy
What I have in mind is the application of a causal theory of moral knowledge to the examination of a feature of moral reasoning which has been well understood in the empiricist tradition since Hume, that is, the role of sympathy [empathy] in moral understanding.
Inherent Capacity for Empathy – [Mirror Neurons] to access human goods and harms [via homeostatic cluster]
It is extremely plausible that for normal human beings
the capacity to access human goods and harms [to inherently intuitively have]
—the capacity to recognize the extent to which others are well or poorly off with respect to the homeostatic cluster of moral goods and
the capacity to anticipate correctly the probable effect on others’ well-being of various counterfactual circumstances
—depends upon their capacity for sympathy [empathy],
their capacity to imagine themselves in the situation of others
or even to find themselves involuntarily doing so in cases in which others are especially well or badly off.
The idea that sympathy [empathy] plays this sort of cognitive role is a truism of nineteenth-century faculty psychology [psychology FSRC], and it is very probably right.
Empathy is motivational re contingent psychological fact has cognitive and motivational role in normal humans
It is also very probably right, as Hume insists, that the operation of sympathy [empathy] is motivationally important:
as a matter of contingent psychological fact,
• when we put ourselves in the place of others in imagination,
• the effects of our doing so include our taking pleasure in others’ pleasures
• and our feeling distress at their misfortune,
• and we are thus motivated to care for the well-being of others.
The psychological mechanisms by which all this takes place may be more complicated than Hume imagined, but the fact remains that one and the same psychological mechanism—sympathy [empathy]—plays both a cognitive and a motivational role in normal human beings.
Morally unconcerned person suffers a cognitive moral deficit, with deficient in cognitive capacity re empathy & awareness of this moral fact [moral FRSC] – contingent to human psychology FSRC.
We are now in a position to see why the morally unconcerned person, the person for whom moral facts are motivationally irrelevant, probably suffers a cognitive deficit with respect to moral reasoning.
Such a person would have to be deficient in sympathy [empathy], because the motivational role of sympathy [empathy] is precisely to make moral facts motivationally relevant.
In consequence, she or he would be deficient with respect to a cognitive capacity (sympathy [empathy]) which is ordinarily important for the correct assessment of moral facts.
The motivational deficiency would, as a matter of contingent fact about human psychology, be a cognitive deficiency as well.