According to Kant, prostitution is morally wrong. The second formulation of the categorical imperative states that one should never use themselves, or another as a mere means.
1. I can see how prostitution would fail to respect self, as it is using one's body as a "mere means" to earn money. But how is that different from a farmer, who use his body to work in the fields to harvest crops for food and money?
2. Prostitution also fails to respect another, by using the person to satisfy his sexual urges. However, by paying the prostitute, isn't it also respecting her by recognizing her dignity and worth and paying her for her "work"?
On the basis of these 2 points, can you please explain why prostitution is morally wrong?
I'm not sure that most contemporary Kantian moral philosophers agree with Kant on the morality of prostitution. As you note, prostitution does not seem to make use of one's own humanity in a way that's fundamentally different from other forms of work or labor which are clearly morally permissible. Why think that prostitution, unlike farming, involves the wrongful use of ourselves merely as a means? Much of the reason is that Kant was deeply skeptical about the compatibility of sexual desire with the moral requirement to treat rational agents as ends in themselves rather than merely as a means. He writes: “Sexual union is the reciprocal use that one human beings makes of the sexual organs and capacities of another” for the purpose of enjoyment. As Kant saw it, sexual desire is not a desire for a person's good but for the use of their body for one's own physical pleasure. Hence, sexual desire is fundamentally at odds with respect for others' rational natures. Sex is animalistic in that we treat ourselves ...