Jrgensens dilemma means that ought-sentences cannot play a role as the premise or conclusion of a logical inference, for they are unable to be true or false, on one hand; and many inferences taking ought- sentences as premise or conclusion are intuitively correct on the other hand. The truth-value semantic solutions try to evaluate the validity of the deontic inferences, by supposing that ought-sentences can also be true or false. These solutions do not remove the dilemma but only circumvent it. A more general concept of logical consequence than the truth-value semantic one should be needed for solving the Jrgensen dilemma, which denies that logic must depend on the concept of truth.