A recent discussion at First Things (published also in the print version) presupposes without argument that it is material:
This presents difficulties of conscience. Because providing and paying for the coverage is required, in one way or another the contraceptive mandate involves what moral theologians call “material cooperation with evil.” Of course, as taxpayers, voters, and loyal citizens, we inevitably are implicated in the goods and evils of American society. In some instances our material cooperation with illicit acts and moral evils, if indirect, may not be culpable, and moral theologians will rightly debate the details of material cooperation with the contraceptive mandate as it applies in various circumstances.
However, one principle is clear: We should always seek to withdraw support and reduce material cooperation when possible. The failure to do so sends a message. It suggests that our material cooperation flows from assent, all the more so when we do not take the available steps to disentangle ourselves.
The supposition is not unimportant for the purposes of that discussion. Formal cooperation in an inherently wrong act is itself inherently wrong. So if the mandate compels formal cooperation, then it simply cannot be acceded to—not as a matter of what the authors refer to as “civil disobedience” (which then gets assessed in relation to its visibility, effects, and cost) but rather simply as a matter of intergrity and moral lawfulness, along the lines of “we must obey God rather than man.” (I take it that to refuse to participate in evil is not “civil disobedience.”)
Briefly, formal cooperation involves participation in something; material cooperation involves providing conditions or instruments for something. A clear example is the difference between the stagehands who set up the music stands and chairs on stage before a concert, and the musicians of the orchestra who follow next upon the stage and actually play the music. Although the performance could not go on without the work of the stagehands, the stagehands cooperate only materially with it, whereas, say, the triangle player who just sits there and has no notes to strike in a piece nonetheless is cooperating formally with the orchestra’s performance, since he is a member and participant.
Sometimes moralists say that formal cooperation is distinctive because it engages the will directly: it involves some aspect of willing or intending that which one cooperates with.
Now one would think that the mandate compels formal rather than merely material cooperation, for these reasons:
1. Any benefit which an employer provides is offered to the employee as something which the employer regards as good. That is precisely why it is called a “benefit” and is thought to be connected with the goals and mission of the organization. If the employer can claim credit for a benefit which truly is good, then he likewise gets responsibility for a benefit which is bad. That is, the purpose or will of the employer is engaged. The character of the benefit makes a statement about the employer’s conception of what is good, and to compel that something bad be provided as a benefit, is to insert something bad as included in what the employer is offering as good. Hence something offered as a benefit is cooperated in formally.
2. What we share in paying for, subsidize the costs of, or jointly provide with another, is usually something we are participating in formally.
3. Compulsions which are material are “uncomfortable” (e.g. the postman who must deliver pornographic magazines sent to a certain address) but compulsions which are formal are sensed as being “violations of conscience.”
4. The language used by bishops and other authorities to describe the noxiousness of the mandate suggests that it is meant to compel actual participation in something wrong.
5. Insurance contracts for immoral actions would seem to imply formal, not material cooperation, e.g. if someone could buy insurance for hiring an assassin to kill dangerous enemies, then anyone who underwrote or subsidized such a policy, it seems, would cooperate formally with him (that is, with the evil intention, at least, of being prepared to assassinate one’s enemies).
6. We can imagine extensions of the mandate which are such that, it seems, everyone would concede that cooperation then is formal— e.g. a mandate to provide insurance for surgical abortions, or for physician assisted suicide—in which case the mandate already would, right now, compel cooperation which is formal.
7. What involves formal cooperation is something that we consider, in a non-defeasible manner, that we would never do; but something that involves material cooperation is something that we consider, in a defeasible manner, that we should avoid. Yet it seems that the reaction of persons of good will and good judgment to the mandate has been like the former, not the latter.
These are my arguments, then, that the cooperation is formal. I won’t state the arguments con, because my concern was merely to show that an unargued supposition of material cooperation appears unjustifiable.
By the way, William Marshner has an interesting discussion which among other things argues that the cooperation is formal (although I cannot agree with his use of the principle of double effect).