Question:
Answer:
This is an area of Catholic moral theology in which we are seeing new developments on existing principles (not changes to doctrine, but developments in how it is to be understood and applied in practice). To the best of my knowledge, the most recent instruction we have from the Vatican that applies to the issue of same-sex unions is Considerations Regarding Proposals to Give Legal Recognition to Unions between Homosexual Persons, issued in 2003 by the Congregation for the Doctrine of the Faith. It states:
In those situations where homosexual unions have been legally recognized or have been given the legal status and rights belonging to marriage, clear and emphatic opposition is a duty. One must refrain from any kind of formal cooperation in the enactment or application of such gravely unjust laws and, as far as possible, from material cooperation on the level of their application. In this area, everyone can exercise the right to conscientious objection (5).
Providing services for a party that celebrates a same-sex union, such as baking a cake, does not rise to the same level of cooperation in the event as does providing services that directly facilitate the union (e.g., acting as the presiding official at the union on behalf of the state). So the short answer to your question is yes. Nonetheless, the CDF document does note that “everyone can exercise the right to conscientious objection” to participation in such an event.
If a baker chooses to not provide his services as a vendor for parties celebrating same-sex unions, I recommend that he contact an attorney to find out his rights and obligations in his municipality. He will need to be prepared to respond appropriately in the event he is asked for a cake to celebrate a same-sex union.