Bhagavad Gita Verse 42, Chapter 3

indriyaani paranyaahurindriyebhyaha param manaha |
manasastu paraa buddhiryo buddheh paratastu saha || 42 ||
 
It is said that the senses are superior (than the body), the mind is superior than the senses, the intellect are superior than the mind, and that (the eternal essence) is superior than the intellect.
 
indriyaani : the senses
parani : superior
aahuh : is said
indriyebhyaha : than the senses
param : superior
manaha : mind
manasaha : than the mind
tu : also
paraa : superior
buddhih : intellect
yah : that which
buddheh : than intellect
parataha : superior
tu : also
saha : that
 
As we approach the conclusion of the third chapter, Shri Krishna delivers yet another profound shloka that has layers and layers of meaning. Let us examine its practical aspects.
 
This shloka provides us a hierarchy of our nature, or our prakriti. Earlier in the second chapter, Shri Krishna provided us with the ultimate goal of the Gita, which is to realize that we are the eternal essence, and are distinct from our prakriti, which comprises the body, mind and intellect. So in this shloka, he further informs us that these three components of our prakriti are not equally powerful - there is a hierarchy or an order to their power. The subtler a component is, the more power it wields.
 
The body is the most tangible, or the most gross, aspect of prakriti. Subtler than the body are the senses. Subtler than the senses is the mind, which generates reactions in the form of emotions and thoughts, but lacks decision making power. Subtler than the mind is the intellect, which can analyze and understand the thoughts generated by the mind, and has the power to control the mind, the senses and the body. And here is the key point: if we assert control of one aspect of prakriti, we automatically bring all the lower levels in our command.
 
For example, let's say someone wants to quit smoking. If he convinces his intellect that smoking is harmful, and also remains alert at the time a desire to smoke arises, he has a good chance of quitting smoking. But if the intellect starts rationalizing this behaviour by saying "one cigarette is not a problem" then there is no chance.
 
Now, if we are operating on the level of our vaasanaas, the intellect is where the hierarchy would stop. Then desires would take hold of the senses, the mind and even the intellect, making us act selfishly. There would be no way out. But this shloka urges us to realize that there is something even superior to the intellect, which has the potential to root our desires that have penetrated the intellect. In the initial stages of our journey, that something is a higher ideal. But as we proceed in our journey, it is the highest possible ideal: the eternal essence itself. Unless we recognize this, we will be stuck at the level of the intellect. This paves the way for the technique of removing obstacles, which is covered in the next and final shloka of the third chapter.
 
Footnotes
1. Bringing one's prakriti under control is one component of the "saadhana-chatushtaya", or the four-fold qualifications of a seeker. Control of the senses is called "dama" and control of the mind is called "kshama".