22. Nefesh and Neshama
Yesodei HaTorah 4:8
The soul (nefesh) of a living creature is the form it was given by God. The extra intelligence in the soul of a human being is the form of man. Regarding this form, the Torah says, "Let us make man in our image and our likeness" (Genesis 1:26). This means that God gave man a form that can understand spiritual ideas such as angels, who are form without matter, so that man might resemble them. This verse does not refer to a person's physical body, which is called by another term, to'ar (meaning "appearance," as opposed to "tzura," which is the word for "form").
It is not the soul (nefesh) of a living creature that enables it to eat, drink, reproduce, feel or think. Rather, daas (knowledge) is the form of the soul. It is this form that is meant in the phrase "in our image and our likeness." This form is often referred to as nefesh or ruach, so one must be careful in his choice of terminology. Each term actually refers to something very specific.
Yesodei HaTorah 4:9
The form of the soul (nefesh) is not a combination of basic elements into which it will eventually decompose, nor does the nefesh originate from the neshama so that it would require the neshama the way that the neshama requires the body. Rather, it comes directly from God. Therefore, when a person's physical form decomposes and his neshama ceases to exist - because a neshama can only exist in combination with a body - the nefesh will not cease to exist, as it does not need the neshama. Rather, the nefesh comprehends knowledge beyond the physical, it knows the Creator, and it exists forever. This is what King Solomon wrote, "The dust will return to the Earth as it was and the spirit will return to God, Who gave it" (Koheles 12:7).