401. The sphere of procreating and protecting what is procreated is a similar progress from the aim through the cause to the effect. In this case the aim is the will or love of procreating; the intermediate cause through and into which the aim introduces itself is conjugial love. The progressive series of efficient causes consists of making love, conception, the gestation of the embryo or foetus being procreated. The effect is the actual foetus procreated. Yet although aim, cause and effect represent three successive stages, they still make one in the love of procreating, and within each separate cause, and in the actual effect. They are merely efficient causes which progress by stages in time, because they are a natural process, although the aim or will or love remains constantly the same. In natural processes aims progress through stages in time without being temporal. But they cannot come forth and exhibit themselves, until the effect or purpose comes into existence and becomes an object. Before this the love could not love anything but the progress, being unable to draw strength and become fixed.
[2] It is well known that such stages have their periods, leading to the preservation of creation in the condition foreseen and provided. The stages of the love of children, however, from its greatest to its least and so its ending, and so to the end at which it stops and ceases to exist, run backwards, since they depend on the diminution of innocence in the object, and also on account of the stages.