Penny, I agree with your distinction in context - a forced sexual partner is a slave to the rapist, and the prostitute is a slave to the pimp. But don't neglect the possibility that prostitution be legal and socially supported (Cardassia? Holland?) where it could really be a job choice, much as (many) Americans would like to think otherwise. I remember minding that the Federation seemed to mind slavery less than, say, psychedelic drug use (remember that episode, Mbo will know the title, where Dr. Crusher figures out that the "remedy for the plague" is really a narcotic, and the plague itself withdrawal symptoms, and they got all high-and-mighty about how awful it was and let's violate the Prime Directive and make sure these people have no fun unless they are sober) - but I digress. However, I was thinking of the many societies where buying the services of a woman, nor offering to sell them, is NOT so frowned upon that the woman's part in it cannot be seen as a choice.