WMM: When war is futile, victory consists of merely staying alive. Survival is the ultimate ideology. Your father wisely refused to believe this.
Mulder: My father sacrificed my sister! He let them take Samantha--
WMM: No. [looking sorrowful] Without a vaccination, the only true survivors of the viral holocaust would be those immune to it: human/alien clones. He *allowed* your sister to be abducted, to be taken to a cloning program. For one reason.
Mulder: [in sudden understanding] So she'd survive. As a genetic hybrid...
WMM: Your father chose hope over selfishness. Hope in the only future he had: his children. His hope for you, Agent Mulder, was that you would uncover the truth about the Project. That you would do everything you could to stop it-- That you would fight the future.
Mulder: Why are you telling me this?
And so back to the rest of the scene....