Using as a mere means

Carl is an inventor and Davita works for a competing company. They are stuck on a deserted island for a week. Carl informs Davita about something he has just invented. Davita is perfectly honest and if questioned in a court of law will testify to what Carl said. In announcing it to Davita, according to the patent laws of their country, Carl establishes the priority of his invention. Davita does not want to help a competitor establish priority. She does not consent to being using in this way. But Carl has no one else to tell about his invention and thereby establish priority.

Carl has used Davita. In fact, he has used her body, by vibrating her eardrums in order to convey to her information that she rationally does not want to hear. But I am inclined—though not extremely strongly—to think that Carl has acted permissibly. It is an important feature of human sociality that we be permitted to communicated messages that our interlocutor does not want to hear, though there are some exceptions, such as facts that will traumatize us, or that violate the privacy of someone else, or that are selected to be misleading, etc. But it is hard to see that Carl’s action falls under some such exception.

Does Carl use Davita as a mere means in the Kantian sense? I think so. Davita does not consent. She is rational in refusing to consent.

I am inclined to conclude that Kant is simply wrong about a blanket prohibition on using others as mere means.

But there still are cases where such a prohibition stands. For instance, in sexual contexts. So I think the prohibition on using others as mere means depends on substantive features of the situation.

All that said, I am not completely sure about the case. Carl does seem sneaky. If I were Davita, I would be annoyed with him. But I don’t think I could morally object to what he did. It would be like the annoyance one has with an opponent in a game who exploits one’s weakness.