The following is an addendum of a letter by the Rebbe sent in 1944 to R. Menachem Zev Greenglass, one of the leaders of the Lubavitcher community in Montreal, in reply to a condolence letter he received from him after the passing of the Rebbe's father, Rabbi Levi Yitzchok Schneerson, on 20th Menachem Av of that year.
There are [four levels] within a person: a) the G-dly soul, b) the intellectual soul, c) the animal soul, and d) the body. (It is possible to explain that these four levels correspond — in ascending order — to the four [forms of existence]: inanimate matter, plants, animals, and humans.)
a) The G-dly soul is “an actual part of G-d from above.” If it falls from this level, i.e., it loses its desire to cling to G-dliness, it can be called “dead.” The advice [to correct] such a situation is meditation and conduct according to Chassidus.
b) The intellectual soul: Its purpose is to enable the animal soul to understand how to control its emotional qualities through intellect and reason. A child — one in years and one in knowledge — has very strong emotional drives and his intellect is modest. If his intellectual soul is drawn after its desires, even those which are permitted, [acting like] an animal, he has fallen from his level and is considered as “dead.” The purpose of chinuch is to set him up [on the path of] proper conduct.
c) The animal soul should — according to its natural tendency — resemble the other animals and beasts which do not change the missions they have been given. If it transgresses and violates the will of its Creator, it has fallen from its level and is called “dead.” [As our Sages comment:] “The wicked — even during their lifetime — are called 'dead.'” [This continues] until he is aroused to teshuvah and the strengthening [of his observance of] the Torah and its mitzvos through [gentle] rebuke and encouragement by his colleagues. He then returns to “the camp of Israel” (Machne Yisrael).
d) The body: its purpose is to serve as a medium for the soul. When the connection between them ceases, [the body] falls from its level, dying, in the literal sense. It is the responsibility of the members of the Chevra Kadisha to prepare everything to be ready for the Resurrection of the Dead; may it come speedily.
May G-d enable us to merit the fulfilment of the prophecies: “And death will be swallowed up forever,” - “And on the third day, He will raise us up, and we will live before Him” with body and soul, joined together.
