This Article explores one of the naturalization requirements that every state has implemented in his citizenship law. Yet, the issue is not widely searched mostly due to the absence of research resources. While proving a negative criminal record is an objective condition, the good moral character or not being a threat to the society is subjective which means that the state may have wide discretional power in deciding which extent may be a danger to the society the individual applying for naturalization. We live in a world where the value of state security is evolving thus it is a legitimate expectation from the side of the state to exclude as much as possible a threat to the society. In the interest of safety, states may formulate their national laws in such a way that even in the case that all requirements for naturalization are formally fulfilled by the individual, the state may have the right to refuse the full admission of an individual who is suspected of being dangerous to the society.