Answers to questions, as well as solutions to problems in Rizal's Noli me Tangere and El Filibusterismo, can best be found in his essay 'The Indolence of the Filipinos'. A key concept of Rizal is that of 'national sentiment'. Rizal believed that the lack of national sentiment was the cause of the numerous ills of Philippine colonial society. Rizal's criteria for identifying these problems, and how to eliminate or prevent their recurrence in Philippine society, is still cogent for many more years to come.