Lal: Father, what is my purpose?

Data: Purpose?

Lal: My function, my reason for being?

Data: It is a complex question, Lal. I can only begin to answer it by telling you that our function is to contribute in a positive way to the world in which we live.

STAR TREK: THE NEXT GENERATION, USA 1987-1994. THE OFFSPRING, Season 3, Episode 16, R: Jonathan Frakes, W: René Echevarria, first aired: 02.03.1992, TC: 00:13:55 - TC: 00:14:17.