All three words can mean something like "soul", e.g., neshama in גלגול נשמות, and ruach in וַתְּחִי רוּחַ יַעֲקֹב אֲבִיהֶם (Bereshit 45:27). So, what is the difference?
The names of nefesh, ruach, neshamah, yechidah, chayah (in that order) is from Bereishis Rabba 14:11.
I wish to add two more positions to the discussion.
The first is Rav Saadia Gaon's (Emunos veDeios 6:3). Rav Saadia Gaon was an Aristotilian rationalist, although to a lesser extent than the Rambam, who had to deal with the topic when writing a commentary to Seifer haYetzirah:
According to Rav Saadia Gaon, there is one indivisible soul, but it has three sets of abilities -- the emotions that draw us to people and things (desire), those that drive us away from them (anger), and thought. The soul has different names, depending upon context, upon whether we are talking about one of these three abilities, its ability to persist, or its uniqueness
The other opinion I wish to add or perhaps two opinions, is that of the Vilna Gaon and R' Chaim Volozhiner:
R. Chaim Volozhiner explains Nara”n based on the breathing imagery used in Bereishis 2:5:
וַיִּיצֶר֩ ה אֱ-לֹקים אֶת־הָֽאָדָ֗ם עָפָר֙ מִן־הָ֣אֲדָמָ֔ה וַיִּפַּ֥ח בְּאַפָּ֖יו נִשְׁמַ֣ת חַיִּ֑ים וַיְהִ֥י הָֽאָדָ֖ם לְנֶ֥פֶשׁ חַיָּֽה׃ And Hashem G-d formed man of dirt from the ground and He breathed into his nostrils a living neshamah; and the man became a living nefesh.
Rav Chaim writes (Nefesh haChaim 1:15):
The soul is likened to the breath of air that a glass blower uses to inflate hot glass. The Nefesh haChaim, following a far older metaphor, breaks down both processes into three parts. The first is the air, as it is still in the glassblower’s cheeks. This corresponds to the neshamah, the part of man which is most connected to Hashem. When the air leaves the glassblower’s mouth, it flows down a tube. The tube connects the glassblower and his work. In the same sense, the ru’ach dwells in the connection between the physical and the spiritual. This flow, a wind, is the ru’ach. From the tube, the air enters the glass, “dust of the ground”. This is the nefesh, giving shape and purpose to our physical selves.
This metaphor gives us another description of how the ru’ach, by being the decisor, also becomes a source of desires. Recall that I started this series with the notion that the ru’ach, man’s existence in the world of his own mind and in a relationship to himself, was a the person between the angel and the little devil propped on his shoulders. And yet now we’re saying it has desires too! The ru’ach is the connection between the nefesh and the neshamah, it exists because of the tension between being both Divine “breath” and clothed in earth. Yet, because it sits in this middle world, the ru’ach is also an entity in its own right.
The the Vilna Ga’on is in his discussion (Peirush al Kamah Agados, Koenigsburg ed. pg 10b) of the following gemara:
The Gaon explains that the house in the air is clearly a reference to the ru’ach, suspended between heaven and earth. (After all, the word “ru’ach” also means “wind”.)
The ru’ach has the ability to decide, and thus the concept of Free Will. With will comes a desire to see that will implemented, to make the worlds outside ones head match the world as we imagine it could be. With will comes a hunger for power and control. Rather than being the means to get things done, they can take over and satisfying them can become an end in itself.
A person has control over an object when he possesses it. And money gives a person more opportunities to get more of his dreams accomplished. When, sadly, someone turns it into an end in itself, they can never be satisfied. The hunger is for a means, which can only be put to trying to get more. “He who has 100 zuz, wants 200.”
This is an aspect of the nefesh as a whole. It’s clear that the role of mitzvos between man and himself are not given the same central role in Jewish discourse as those between man and G-d and between man and other people. This is because they are not an end. The point is not self-contemplation. To be the perfect self is to be perfect in one’s relationships, the same three relationships.
… including the relationship with oneself. This self-reference is a concept that comes up often when dealing with the concept of intelligence. And self-awareness, consciousness of one’s own thought, is the essence of the nefesh, of making Free Willed choices.
In this Youtube video (5:49 seconds in), Rabbi Chaim Miller explains that:
He does not bring his source.
Accoding to the Rambam in "the Guide of the Perplexed", (and WAF above), the meaning of the words in each individual case are to be determined by the context."
According to Jewish Magic and Superstition: A Study in Folk Religion (admittedly, not the best source.)
The Neshama goes up to Hashem (olam ha-ba and techiat hamatim), and both the ruach and nefesh remain on earth. The Ruach stays with the body and never leaves it. The week after death, the nefesh wanters between the deceased's' home and grave, then infrequently comes returns to the grave until it is weaned from the grave by the end of a year.
I've seen it explained as follows (in Wisdom, understanding, and knowledge: basic concepts of hasidic thought):
Nefesh - Every creating thing in the world has a Nefesh, the G-dly force that gives it life. Inanimate objects (such as rocks) have only this. (see here)
Ruach - Every living thing has a Ruach as well, the life-giving force that animates the living thing. (see here)
Neshamah - Referred to in Tanya as "an actual part of G-d". This is only found in the Jew. (see here)
Note: I've linked to the snippets view of google books searches. This is not ideal. If anyone knows of a better online source that says the same thing, please let me know.
The Maharsha in his Chidushe Aggadot (3A, d"h "Mishmorah Rishonah Chamor") says almost the exact same thing. He says that there are 3 parts of the soul of man which are called "The Natural", "The Life", and "The Intellect". He says that Kabbalists call them the "Nefesh", "Ruach", and "Neshamah". See there for a little more elaboration.
In Kabbalah or Chasidut Nefesh means a bodily soul, or instinct, or inate. (All created things have nefesh). Ruach is often used in the context of "Ruach Hakodesh", which is a sort of divine inspiration, or an aspect of godliness /correctness of thought (morality is one example of that). Ruach can also be the basic life force of any living thing. Neshama is the higher level soul which is connected directly to Gd, it exists only in humans.
Outside of Kabbalah, Nefesh is the life force of any living being. Ruach is the animator of life, its what allows things to move, and Neshema is the combination of Ruach and Nefesh.
Nefesh can mean either "breath" or something like "life force". "Ruach" is usually used to mean "spirit" in the sense of "enthusiasm" or "vigor". Not sure about neshema and how it differs from nefesh.
EDIT: Wikipedia has a concise summary of the kabbalistic usage:
Nefesh is the brain, so it can die. Thinking animals have a nefesh. However, ruach is immaterial; not physical. Ruach is your holographic-like personality software that develops in your nefesh hardware brain. Animals do not have a ruach with higher level thinking and consciousness. As software can be transferred from one computer through a network to another computer, when you physically die, your ruach will be transferred from your hardware brain through the logos (universal neural network) to either Heaven (New Jerusalem) or Hell (the grave Place of Torment, and later the Lake of Holy Spirit Fire). People have often wondered how the nefesh and ruach can be different if they both think and feel emotion. Now you know, it's because the ruach is the personality software that develops in the nefesh hardware.
protected by msh210♦ Sep 8 at 5:42
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