D&C 132
The purpose of plural marriage is to multiply and replenish the earth. A husband can take multiple wives only when all of the following conditions are met:
- He does so for the purpose of multiplying and replenishing the earth when the current wife (or wives) cannot or will not accomplish that goal further as he is striving to do
- He does so with the consent of the current wife (or wives)
- He does so through the proper authority