Getting a second cat, heaven or hell?

Cats are considered lonely and independent creatures. Sometimes they do enjoy the company of another cat, other times the cats keep fighting and never really accept one another. It may or may not work - depends upon the personality of the cats.
Many people believe they should get a 'companion' for their cat because they feel guilty when they are away all day. The fact is that most adult cats sleep most of the day and could care less about a companion as cats are basically solitary animals. While some cats thrive in the company of another cat, other cats get upset about having an intruder in their domain.
If your cat is comfortable in his home she probably won't appreciate a new cat coming into her territory. It can be hard work introducing a new cat into a home with a cat already there. They will probably fight for dominance and hate each other. However they would eventually get used to each other and probably be civil with the occasional smack every now and again. Some cats don't mind and get on well straight away, but there's normally more fighting than fun!
An important thing is that the new and existing cat are introduced slowly and carefully. The new cat has to be given time to get used to you and the new environment. The existing cat has to get used to the smell of the new cat.