Having a Conscience

Sometime I wonder if all human beings have a conscience. More recently, I have come across some people that do and say things and have no idea that they are hurting others. Do they just not care or do they just not know? I always thought that we are at a higher level than animals. I am now questioning that thought. The other day, my dog, Shelby, had an accident on the den floor. I was upstairs and he had no way of letting me know that he needed to be walked. He always barks at people walking by the house, so I did not go to check on him, when he barked, this time. He had no choice but to "go" on the carpeting. Normally he loves to sit on the den couch. When I came downstairs, he was in the kitchen, in his bed, with his head down and his tiny paws covering his eyes. He knew he had done something wrong and gave himself a "time out" as punishment. Then it dawned on me. He has a conscience. He has the thinking capacity to know right from wrong and to feel bad about it. If a small dog knows, why don't people?