There is a parallel explanation expounded in the esoteric teachings of the Arizal concerning the function of the Kaddish prayer in the order of the daily prayers. The purpose of the Kaddish, according to this interpretation, is to effect an ascent from spiritual world to spiritual world, from Asiya, to Beriya, to Yetzira, to Atzilus. These worlds are represented by the four stages of prayer alluded to in the allegory of the “ladder standing on the ground and whose top reaches the heavens1.” There are four rungs on the ladder and there are four ascending points in the morning prayer at which the Kaddish is recited. These “Kaddish steps” allow the individual to rise to the highest world and then to reach another four descending steps on which the revelation of above may be brought down into the reality of the world, again through the recitation of Kaddish. (There are a total of sixteen Kaddish recitals during the three daily prayers and they form a construct of this rising and descending process.)

When we study the meaning of the Kaddish text we see that in fact we are speaking of very lofty ascents:

Yisgadal— exalted and hallowed be His great Name2.

In essence we are effecting an increase (as it were) in the greatness and holiness of the Holy One, Blessed be He. For we pronounce: “May His great Name be blessed....” We are able to effect increased blessing even in G‑d’s great Name.

We may now perceive how the recitation of Kaddish after the departed soul of a righteous person will cause an ascent for the soul, to rise from lofty level to loftier levels in the Garden of Eden ("paradise").

Further elucidation is needed at this point.

Simple observation tells us that there is one text for the Kaddish. We say the same Kaddish for a Tzaddik, with the intention of helping raise the soul to the highest level of the Garden of Eden, and we recite the self-same Kaddish for our dear departed loved ones who were not so righteous in their lifetime. We even use the same text when we recite the Kaddish for a person who would need Kaddish to be said for the full twelve months!