According to St. Alphonsus Liguori, the required seriousness of a “proportionate reason” for partaking in remote cooperation depends on two factors:
- How grave the bad effect/sin is, and
- How remote the cooperation in the sin is
Many companies support Planned Parenthood (PP), which performs abortions. Buying something from a company that supports PP would have a bad effect that is grave - some of the money would go to PP to be used for funding abortion(s). The cooperation in the sin of abortion would be very remote, though, which might diminish the seriousness of a proportionate reason for supporting a company that supports PP.
However, there is a similar situation of remote material cooperation that would definitely be wrong: voting for a pro-abortion candidate when the “proportionate reason” for doing so is improving workers’ rights, or protecting the environment, or improving the economy, etc. We know that the only time voting for a pro-abortion candidate would be justified is when one wishes to keep even worse candidate(s) out of office. For example, if I must choose between Candidate A, who supports abortion but is against euthanasia, and Candidate B, who supports both abortion and euthanasia, I could choose Candidate A in order to prevent Candidate B from winning. As one can see, the seriousness of the reason for voting Candidate A must be very grave, even though the cooperation seems to be very remote in this situation; indeed, the effect of my individual vote is tiny among the millions of other votes.
In both situations, the bad effect is abortion(s) being performed, and the cooperation in this evil is quite remote. We know that a proportionate reason for voting a pro-abortion candidate must be very grave.
Therefore, we can conclude that a proportionate reason for supporting a company that supports Planned Parenthood must also be very grave. Reasons such as cheap prices or convenience would not constitute a grave reason to support such a company.
