The teaching of the Magisterium on this point has already been stated.[51] This teaching is not just an expression of particular historical circumstances but is based on the Church’s doctrine concerning the connection between the conjugal union and procreation and on a consideration of the personal nature of the conjugal act and of a human procreation. “In its natural structure, the conjugal act is a personal action, a simultaneous and immediate cooperation on the part of the husband and wife, which by the very nature of the agents and the proper nature of the act is the expression of the mutual gift which, according to the words of Scripture, brings about union ‘in one flesh.’”[52] Thus moral conscience “does not necessarily proscribe the use of certain artificial means destined solely either to the facilitating of the natural act or to insuring that the natural act normally performed achieves its proper end.” [53] If the technical means facilitates the conjugal act or helps it to reach its natural objectives, it can be morally acceptable. If, on the other hand, the procedure were to replace the conjugal act, it is morally illicit.