Which idea, other than economic exploitation, was behind French colonization of Vietnam?

French colonization of Vietnam was based on ‘the idea of civilizing mission’, apart from economic exploitation.

NOTE - The French attempted at bringing ‘modern civilisation’ from the advanced Europe to Vietnam. Education was one such tool of modernising the Vietnamese. The curriculum at the educational level was manipulated in such a way that the Vietnamese could only acquire qualifications that would create a labour force for the French to carry out their tasks because a highly educated class of Vietnamese would pose a threat to the jobs of the French in Vietnam.

For example- the textbooks often glorified the French and justified colonial rule.