noun. The act of perpetuating or making perpetual; the act of preserving through an endless existence, or for an indefinite period of time; continuation.

noun. The act of making perpetual, or of preserving from extinction through an endless existence, or for an indefinite period of time; continuance.

noun. The act of prolonging existence, of keeping something alive or active.

noun. the act of prolonging something

"In other words, your definition tells that the passion for perpetuation is the cause of love, and perpetuation the end to be accomplished."