Common Sense is one of the things we desperately need, and it is the ability to think in first principles. An ability to takes the observations fed to you by the environment, and to understand where they do not fit together logically. Unfortunately many seem to have lost this ability, as they are flooded by way too much information for humans to process.
If you were to talk to Charles Simon, he would tell you that we shouldn't be aiming for Artificial Intelligence, which requires massive amounts of input repetition to learn things. Sure, brute force as this approach is, it has been a workable solution until now, but it is possible to arrive at a solution that requires far less repetition, as it stores its knowledge in a graph structure, and uses natural language processing in order to fill this structure. So that is what Simon is saying, and he names it Artificial Common Sense, or ACS for short.