Why was the practice of Sati started?
I think that this becomes a very complex issue. On one hand, I believe that the practice of Sati was originally envisioned after the idea of absolute devotion. In this, one has to look at the Goddess for whom the name of the practice is derived. Sati is so devoted to Shiva that she cannot bear the idea of him being disrespected. Rather than endure such torment, she immolates herself to demonstrate both her loyalty to her husband and her absolute rejection of her father, leading the insulting of her husband. From this, a practice of devotion is where sati received its inspiration. It was not a practice only limited to women. Any loved one engaged in it when they could no longer bear the separation from a loved one. Over time, though, the practice of sati ended up being more geared towards women. It moved to a point where women were being encouraged to engage in the practice when husbands died. It is here where one might see how the fledgling roots of the practice, something where pure devotion and selflessness was evident, became coopted by men in the position of power who wished to reduce the power of women. It is from here where the modern practice of sati becomes an issue of sociology in India from a point where it could have been seen as spiritual.