PML-N President Muhammad Nawaz Sharif has said that the solution to internal and external problems lies in following the philosophy of ‘Ishaq” and “Khudi” of Allama Muhammad Iqbal that gives the lesson and courage to maintain self-respect and protect security and sovereignty. In his message on Iqbal Day, Nawaz said Iqbal is not only the poet of Muslims of subcontinent but he is the poet of the Ummah, and indeed, for the whole humanity.