It's really up to you. If you had a really wonderful time with him and felt like all you didn't like was his looks, then I would say why not... go on a second date, and maybe you'll realize that looks aren't the most important thing. On the other hand, if things weren't incredible and you don't think he's attractive, then I'm sure there are other people who would be better for you. I would try to put aside the looks and think about all the other qualities he had, and see if this is a person that you could see yourself with in the future. If so, then try going out with him again. Good luck.