Fetos is an allegory of the process of life. What would happen if a fetus became conscious in its mother's womb? It would interpret its' surroundings as its only reality. If he found another fetus, his twin brother, he would explain to him what he has learned. If later a third fetus appeared who did not agree with the other two that the womb is the only reality, and it proposed a different possibility. The first two fetuses would reject it. Only the one that understood the process would be born. In order to be born it is necessary to die.