Rizal tried to use history and historical revision not just to express his personal vies on the historiography, but to create a sense of national consciousness or identity.
...that "observations on the conduct of the European conquerors and civilizers are in general not new to the historian. The Germans specially discussed this theme."
The different treatment between Filipinos and Spaniards in Rizal's time induced Rizal to study his country's past. To achieve his goal, he needed impartial and authoritative sources. In his youth, Rizal had heard of a book written in 1607 about the Philippine Islands and their people as they were then. Sucesos de las Islas Filipinas was written by a blunt and honest Spaniard, Antonio de Morga.
Antonio de Morga had written this book, to tell the truth about the conditions of the Philippines and of its native inhabitants at the time of the conquest. De Morga was a reliable source because he observed the country when he accompanied one of the earliest Spanish expeditions in the country for seven years.
Morga's Sucesos is perhaps the most impartial history of the first years of the conquest because it was written without any bias or prejudice, which was the characteristics of the majority of the sources at the time. His work was not well-known because he did not favor any religious organization of the country and which abuses, he denounced and criticized.
They had a culture on their own
The present state was not necessarily superior to its past
They were decimated, demoralized, exploited, and ruined
Rizal's edition of the Morga involves footnotes (annotations) that according to Quibuyen (2008) performed the functions:
They make cross-reference to other early chronicles;
They draw contrasts between flourishing pre-Hispanic Filipino society and culture on one hand and to demonstrate the destructive effects of Spanish Colonization;
They highlight similarities in folkways, religion and languages among various regions in the archipelago;
They show the precolonial linguistic and cultural, as well as trade relations between Vietnam, Cambodia, China, Japan, and the Pacific Islands to situate the Philippines as an integral part of the Asia-Pacific region;
They exposed the falsehood of the "white mythologies" and thereby, deconstruct Spanish Orientalism
Philippine precolonial culture and society;
The immediate impact of conquest, such as depopulation, the decline of agriculture and native industries, and the destruction of the native culture;
The long-term impact of colonial rule;
Some examples of Rizal's deconstructive moves against Spanish colonial discourse;
Rizal's hypothesis about why the Philippine society succumbed so easily to Spanish conquest.