Chasidus speaks at length about the doctrine of two souls.  Particularly, the Alter Rebbe's Tanya describes the nature of these two opposing spiritual forces which are called the animalistic soul and the G-dly soul.  In short, the animalistic soul is the drive for self-preservation, the life-force and the will of the body.  The G-dly soul is the force that craves unity with G-d above all else.

Tanya teaches us to appreciate the true purpose of our existence and empowers us to choose behaviors that serve as an outlet for the G-dly soul.

But the question is asked: "Who does the choosing?"

The simple answer is "you."  "You" do the choosing.  Why does it have to be any more complicated than that.

But you ask, "Who am I?"

Okay, let's got complicated.  In technical chasidic terms, the "you" that chooses between the animalistic soul and the G-dly soul is actually another soul called that rational soul.  Before we procede, a point of clarification is in order.  In English, the word "soul" carries with it certain unwanted connotations when searching for the proper translation of the Hebrew word "nefesh."  While the English word "soul" implies, well, soulfullness, nefesh is a far less romantic word.  A nefesh is merely a drive or a force which has the potential to animate innert matter such as the body.  Yes, a nefesh is a "spiritual" force inasmuch as it itself is intangible, but again, the English language puts us at a disadvantage because "spiritual" here does not mean holy, altruistic or transcendent.  It just means non-physical much like gravity and magnetism are non-physical, although their effects on the physical are empirically observable.

So, there is this third soul, the rational soul, that does the choosing.  If the animal soul judges everything based on how it affects the self and the G-dly soul's single criterion for evaluating anything is it's gratification of the will of G-d, then the rational soul's basis for choosing what it does is whether or not it makes sense.  The rational soul is amoral.  It is moved by logic, not by sentiment or whim.  It is not concerned with adhering to any particular code or upholding any particular loyalty.  It's only concern is to be consistent.  It interprets stimuli and makes the objective decision most consistent with the information with which it is presented.  That's why the rational soul can side with the animalistic soul at one moment and with the G-dly soul the next.  It's truly impartial -- completely sincere in its readiness to hear out any argument.

Interestingly, the Tanya --which is a guidebook for making better decisions -- speaks very little about the entity that does the deciding.  The Tanya describes both the animalistic soul and the G-dly soul in great depth, yet of the rational soul it hardly makes the faintest allusion.  Why is that so? 

The Tanya doesn't speak ABOUT the rational soul because the Tanya speaks TO the rational soul.  It speaks TO the "you" that makes the decisions.  In other words, the entire book is speaking TO the chooser... ABOUT his choices.

One of my favorite self-help books was written fifty years ago by a Los Angeles plastic surgeon named Maxwell Maltz.  The book, Psycho-Cybernetics, comprised the essence of Maltz's discoveries on the subject of identity and self-image.

Among Maltz's main points and the basis for the term he invented -- psycho (of the mind) cybernetics (computer or a machine) -- is that man is not a machine, but man uses a machine.  That machine is the "goal-striving mechanism" called the mind.  Like any other machine, it has no will of its own.  It is a super-computer which performs those functions for which it is programmed.

In other words, the machine is not moral or immoral.  The machine is not happy or unhappy.  The machine just runs and has no opinion about how it's used.  That's why it can just as well be implemented as a failure mechanism as a success mechanism.  It does whatever YOU tell it to do.

But who is the "you" that orders the machine?  Ah, but this is the thesis of Maltz's book: that self-image is king.  The machine will always work automatically, effortlessly to produce the results consistent with whatever self-image man holds.

In other words, we program our machine by deciding who we are, that is, by way of identification.  So, in terms of Tanya, if we identify with the agenda of the animalistic soul, then the rational soul will make sure that we behave in ways that prove that the animalistic soul is right.  If, on the other hand, we teach ourselves to identify with the G-dly soul, then we quite literally re-program the rational soul to feel logically compelled to make behavioral choices in-line with that which is important to the G-dly soul. 

When we tell the GPS unit in our car that we want to go "home," the GPS doesn't care what we choose to define as "home."  It only knows that it is going to tell us how to get there as quickly as possible.

The study of chasidus is our way of telling the GPS what "home" is.  Chasidus is not entertainment or fun or inspiration.  It is the intellectually rigorous task of re-programming the machine.

Have you heard about the dangers of dihydrogen monoxide?  Here are just some of the insidious effects of DHMO.
Death due to accidental inhalation of DHMO, even in small quantities.
Prolonged exposure to solid DHMO causes severe tissue damage.
DHMO is a major component of acid rain.
Gaseous DHMO can cause severe burns.
Contributes to soil erosion.
Given to vicious dogs involved in recent deadly attacks.
Of course, dihydrogen monoxide is none other than two hydrogen atoms bonded to a single atom of oxygen, better known as H2O.  Dihydrogen Monoxide is water.  (See more about the dihydrogen monoxide hoax.)

All year round in the Holy Temple in Jerusalem, the priests would pour libation offerings of wine upon the alter.  On Sukkos, however, there was the special "water libation" in which simple water was offered before G-d.

The drawing of the water on Sukkos was the cause for much joy.  As the Talmud declares, "One who has not experienced the joy of the water drawing festival has never experienced true joy in his life."

What was the big to-do about this unusual offering?

Chasidus explains that there are two kinds of spiritual experiences.  One is likened to wine for it appeals to our senses and arouses our hearts and minds even to the point of intoxication.  The other kind of spiritual experience is much more plain.  Like water, it is life-sustaining but lacks any special taste or appeal. 

A wine-like spiritual experience is typfied by the rousing stimulation of deep meditation, fervent prayer or focussed study, whereas the spiritual experience that is like water is far more subtle.  It is the simple, tasteless experience of surrender -- when one submits to the will of G-d without any particular feeling or understanding.

So again, what is the cause for such joy in simple surrender?

The answer lies in the difference between wine and water.  Ask a thirsty man in the desert which drink he prefers.  The sophisticate and the deep thinker are like the vinophile with discerning pallate.  They are unmoved by water.  They hardly notice it.  They see thier drink as a sensorial experience.  But the simple Jew knows the pleasure of plain water.  He knows the bliss of receiving pure life even when it does not stir the senses.  For in his tasteless, colorless, odorless drink is the greatest pleasure one can experience -- the pleasure of life itself.