| Supposedly because it detracts from the experience of true love -- desire for someone on basis of their physical parts and not the essence of their being (soul) is a bestial approach to coupling.
Christian (and possibly Jewish / Islamic, although I am more uncertain on those points) condemnation of lust derives in large part from Plato's writings on the subject (see his dialogue, Symponsium).
Personally, I think distinguishing lust from personality attraction was a big mistake, as the two are best taken together if an effective relationship is to be developed. Many contemporary theists take this view, although they are likelier to use the word 'sexual attraction' than 'lust', because of the negative connatations of the word in their faith.
A moral being is an entity for whom the disadvantage of others is an issue.
– K.H.Y. |