Evil Depends on Circumstances

Since good and evil depends on the circumstances, the following is true to me:

If one believes that a medical condition allows one to commit an act which violates a precept without harming others, then it is a necessary evil.

A good example is the fact that an orgasm for a male prevents and/or delays the onset prostrate cancer.

Since the easiest way to have an orgasm for a man is to masturbate, then the sexual "sin" is forgiveable due to medical expediency.

However, one should not pretend that the sexual act outside of marriage is condoned by confusing masturbation with coitus.

While the person who masturbates uses sexual fantasies which may involve sexual misconduct, because it is a mind-only delusion necessary to prevent future suffering, one won't go to Avici Hell for such a transgression.

But it is immoral to fantasize about seduction of bodhisattvas, since that could harm one's rebirth in such a way as to condemn him or her to the most difficult of births, that of a human being.