The strength of a claim to conscientious objection depends on the type of law.

An intuition I've been trying to articulate, but naturally Raz did so first (and way more clearly than I have been able to):

On p. 286 of The Authority of Law, he describes how the strength of a claim to conscientious objection depends on "the ground for having a particular legal duty." He describes three categories: paternalistic laws (with respect to which CO claims are strongest), "laws protecting the interests of identifiable individuals" (with respect to which CO claims are the weakest), and "duties to protect the public interest," which occupy an intermediate position between these two. I think this is an important point in relation to the pharmacists' situation, since the requirement to dispense Plan B is an example on the third category, but it is often mis-treated in the literature as an example of the second.

Paternalistic laws
A prima facie right to conscientious objection grounded in humanism is strongest w/r/t paternalistic laws, because "it is hard to imagine a situation in which coercing the conscience of a normal adult by law in his own interest could be justified. If the ideals of autonomy and pluralism are not enough to enable a person to pursue his moral convictions at his own expense then they count for very little indeed." (283)

Laws protecting the interests of identifiable individuals
(e.g., "murder, rape, libel, or even violation of property or contractual rights")
These are the sorts of things that are punishable by tort liability, equitable remedies (e.g., injunction or specific performance), or even penal measures. The idea is that, even a "humanistic" (which is Raz's name for a society that respects individual autonomy) society will restrain individual freedom of action "when vital interests of other people are involved. When this is the case those others should not be made to pay for the conscience of objectors." (284) Penalties (at least financial ones) can be seen in these cases as not violative of autonomy but a "reasonable price for it," akin to alternative service vis-a-vis conscription.

Laws protecting the public interest (i.e., laws protecting the interests of unidentifiable individuals)
"Here the claim not to have one's conscience coerced encounters less powerful opposition from other considerations...[because] of the insignificance of each individual's contribution...Most of the time exempting a single individual from the duty will make little or no discernible difference to the protected good."

Now, the literature criticizing the pharmacists almost invariably describes the conflict as between an individual pharmacist's conscience and the good of an individual woman, suggesting in some cases that the pharmacist should not be able to inflict a harm on the woman because his moral convictions are at odds with hers. I have always found these chracterizations to be odd and misleading, since it strikes me that refusing to provide something is not inflicting a harm, so long as that thing is otherwise adequately provided for. And at the very least, it's a wholly different kind (i.e., in character, not merely degree) of "harm" than that pharmacist might inflict by assaulting her or plowing his car into hers. I wonder how analyses of these different kinds of laws would have to be reconceived on a natural law view, rather than Raz's "humanistic" one, but I am encouraged to have my intuition affirmed that there may ways of defining or delimiting the appropriateness of moral dissent from a law based on the type of duty it imposes.

Question about the appropriate treatment of the conscientious objector

So, Raz points on 281-282 of The Authority of Law that a "right" to conscientious objection could be rooted in the notion of respect for persons, since a society that values autonomy must value pluralism, and such a society will presumably strive to be an environment in which people can pursue their tastes and inclinations in any way they like, subject to the constraints imposed by "the necessities of social cooperation and of securing similar opportunities to all." In that society, if one could explain how a person's freedom to avoid wrongdoing (by his own lights, even if he is wrong) is "central to his self-respect," one has grounds for a right (against society) not to have one's conscience coerced (albeit a prima facie right).

Could a right to "conscientious objection" in a society founded on natural law principles take this form? Perhaps one constituent of an individual's good is self-determination, requiring as a necessary condition a degree of freedom to act on one's own moral judgments. In that case, the argument that society ought to respect my freedom to act on my own conscience seems to take the same form (and be similarly pf, since the fact that the right can be overridden by other values or ideals is "inevitable, given that it is a right to do that which is in fact morally wrong which is given to people who will use it for that very purpose. To give it absolute importance is to prefer the morally wrong to the morally right whenever the act has misconceived moral ideas however wicked.").

But what if the right to act on one's conscience (however evil its dictates) is not a negative right borne of the importance of respect for my autonomy but is instead based on the fact that law has its authority only in virtue of my consent to it, on the basis of its service to the common good? So it's not that individuals' consciences being free from constraint is affirmatively valuable to society but that, lacking free consent from individuals' consciences, society has no authority over them.

Does this change the nature of the questions that need to be answered about CO? Could we still ask "when does the right not to have one's conscience coerced have to give way to other values and ideals?" (AKA, "is the right still prima facie"?) Or would conscientious objection be an absolute right, since the authority of any other legal requirements (including those that serve what might be regarded as "competing" values in a different system) depends on free conscientious consent? And wouldn't we have to consider how a society can maintain de facto authority over its citizens if it is broadly acknowledged that the legitimacy of its authority over any of its individual members is contingent upon her consent?