In cases as above, can the remarks or expressions of the criminal defendant be deemed to have been made “sufficiently transparent for the whole world to recognize the speaker?” This is above and beyond lawmakers’ expectations and is not to be demanded by legal reasoning. A person develops his/her sociability by verbally interacting with others. A person’s speech is the most important means to connect him/her with others and have a social relationship. The freedom of speech is the crucial right constituting the freedom of expression. As the proverb, “bad news travels fast,” words per se have propagation possibility. Punishing on the sole basis of the propagation possibility regardless of whether words about others are true or false is inconsistent with the fundamental nature of humans and continues to pose a threat to the freedom of expression that is constitutionally guaranteed. Therefore, the reason why criminal defamation requires publicity as a constituent element is to provide the space to breathe in consideration of the fundamental nature of humans as above. In terms of guaranteeing the fundamental rights under the Constitution of the Republic of Korea, recognizing publicity on the grounds of propagation possibility is not desirable even with regard to individuals’ private conversations as the cases dealt with in the above Supreme Court decisions. The term “propagation possibility” means that such result has not occurred in reality but has potential for future dissemination. Viewing the assumption that there is “possibility” of being propagated in the future in a situation that such consequence does not occur as the ground of punishment is contrary to the principle of legality. Circumstances remain unchanged even when possibility changes to probability. Recognizing publicity merely on the sole basis of propagation possibility means that an act of defaming another person’s reputation - an act that there is a risk of being defamed according to the Majority Opinion, which views defamation as endangerment offences - is subject to punishment on the grounds that there is a “possibility” of becoming public through propagation even in the case where it is not “publicly” done. Such interpretation corresponds to unjust extensive and analogical interpretation, which should not be allowed as it constitutes interpretation obviously unfavorable to the criminal defendant. C. The theory of propagation possibility is contrary to the principle of legality and the principle of clarity.