The various studies on the text of the Septuagint (LXX) tried, through the comparison of the variants which separated it from the Masoretic Text (MT), to provide for each book a “critical view” on the way the translators have been working. These studies indicate that inside every book we find a certain freedom in the choice of the method. From couple of examples, we are going to see in this article how the earlier translators of the LXX have used these various translation methods in a concrete manner all along their work. It will allow us to understand better why the differences that we find in the LXX in comparison to the MT are not all due to particular readings, nor of the translation mistakes and don’t come from the lack of knowledge or care of the translators.