I would say that is purely on a case-by-case situation. Do you feel like you learned your lesson from the first marriage? Do you feel like you can get through a day without getting mad, sad or frustrated with your ex? If you can't, this is not a situation to start dating someone new. This is toxic and you need time to heal. Jumping into a relationship with someone new when the last relationship is still a fresh wound can be a trainwreck waiting to happen. But, if you were unhappy for a long time in the relationship and out of love for a while, then I would say you're ready. However, I would think if you're asking this question, you're not ready. If you need reassurance, you're not ready.