One of the key roles that the "I" plays in the functioning of the mind is the exrcise of self control.  

Without self control, there can be no evolution to a higher level.  

Ultimately, self inquiry seeks to know what "our" standing is in terms of being able to control our own lives in a world into which "we" have been brought, where nothing seem to be our making and nothing is under "our" influence. 

The fact that we seek to know ourselves implies that we do no know who or what we are. The primary reason for this is that we are a compendium of many different components - Physical (Body, MInd, Senses), Spiritual (Papam, Punyam), Etheral (Atma,Karma).

Anything that can be controlled may be inferred to as representing at least a part of the identity since the object of control does not offer any resistance to being possessed by the identity.  However, none of the following - mind, body, senses, karmic events seem to be under the control of the self. On the contrary all these differernt aspects seem to dictate the exoeriences to which the self is subject to, without its consent!!!

All these elements that we are made up of are interlinked. One does not appear to exist without the other. We deal with each of these forces every minute of our existence. All of them enable our existence and subject us all the time to the opposing sensations of pleasure, pain, success, failure etc. right through our existence. 

The Experiencer of these sensations is understood as "I". The events and the sensations appear preset (our Karma), The experiencer (the "I") wants to avoid the upleasant parts and attempts to use the mind to navigate away from the pain and the failure that Karma offers. This attempted navigation is the starting point of the development of human intelligence. 

Intelligence works by associating cause and effect.  So the effect (which is the pain, suffering and loss) is linked to another event which caused it.  For example if we are driving a car and get into an accident (due to our mistake), the cause is either our oversight of a rule of the road (such as not stopping at a red light), poor visibility, failure of the brake and so on.  Since the cause is our mistake, we can control it and not repeat it in the future by fixing the problem.  We learn to stop at red lights, we fix the brake or by not driving when the visibility is poor.  So the cause of the accident is identified and fixed. 

Intelligence also learns from reading and hearing about the experience of others. It then takes precautions to avoid the same mistakes that others made. 

Lets step back and consider the issue of "who I am".  Am "I" the Experiencer, Or am "I" the one that tries to control the experiences that I am subject to?  Or am I both the experiencer and the one that attempts to control the experiences? 

It appears that "I" am the one that is subject to experiences by forces beyond "my" control. "I" learn from the experiences and attempt to avoid the unpleasant and extend the pleasant by manipulating the cause of these experiences.  

So "I" begins as the experiencer, become the observer and learner and then finally graduates to become the controller of the experiences that "I" am subject to. 

So the identity (the "I") attempts to undergo change from experiencer to learner to controller.  In the process of this attempted evolution, the "I" uses many instruments at its disposal.  The Mind, the senses, the body, are the primary instruments that the "I" attempts to manipulate and control in order to attempt to  "manipulate" it own Karma, so that the "unpleasant" is replaced by the "pleasant". 

SO THE "I" IS THE CONTROLLER (OR THE ENTITY THAT SEEKS TO CONTROL). What does it Control? It tries to manipulate everything under its "conscious control" to ensure that the unpleasant experience is eliminated. What is under its conscious control? The Mind and the senses appear to be "under its control".  The senses are partly under the "control" of the mind.  By the "Mind" is meant the ability to perceive through the senses and relate "Cause" and "Effect" through intelligence. With the information of the cause, the "I" then attempts to manipulate the environment to eliminate or modify the cause of the unplesantness. 

All the three functions ("I", Intelligence and Senses) are centered in the Mind. The Mind is the main contender for the role of the Identity.  However, the Mind is constantly in a state of change.  If, at the point that it tries to become a controller, the environment changes (as it always does), then the Mind goes back to the learning mode!!!! So it is not the controller until this learning process is complete.  

Subconsciously, we seem to define the Identity "I" as something that can Control everything that can be observed and perceived by the senses and make everything do and perform as the "I" WISHES. 
By this approach, the "I" becomes that which can CONTROL. 
By this approach we are moving the center of power from the observed and the perceived to the power that controls and commands (which is what is referred to as the WILL POWER). 
By this approach we are assuming  the observed and perceived objects and phenomena as our "arch enemy" and opponent which needs to be controlled for the survival and well being of us (which is the Identity). When we start the journey inwards to find our own identity, we are essentially dismissing all phenomena that we cannot CONTROL by our own WILL as not being us. We are also dismissing all the observable and perceivable phenomena as not being us. 
By this approach, we are excluding all that we cannot perceive and observe as being beyond the "I" because what is not observed and cannot be perceived is not within cognition and so cannot be "known"/"understood" and therefore cannot be controlled. 
Stepping back a little bit,  it has been proposed earlier that all observed and perceived phenomena are a reflection of our "own" inner self.  "Our Own Inner Self" would essentially mean the identity.  
By this approach all objects and phenomena that are observable and perceivable represent the "I". So the "I" is able to observe itself and using this observation, attempts to control what it observes and therefore attempts to control itself.
But these are observable phenomena. The reflection of these phenomena are projected as the "external world" and are fed back into us through the senses.  
But the "I" is not observable for many many reasons.  The primary reason is that we do not know what it is.  To complicate the issue further, it appears to be in a state of constant change. The "I" appears to be different things at different times. 
The other major issue is - We seem to be clinging to the "I" as the anchor to connect us to- the observable world, our people and worst of all, to the components that we seem to be made up of. 

This attempted exercise of control over the environment into which are born, over the people around us and finally over the components of which we are made, provides the clue as to who or wht that identity is. HERE BEGINS THE JOURNEY OF THE INQUIRY INTO THE SELF.