Lacan : explanation and application

Jacques Lacan created the idea of lack and instigated that said lack causes desire to rise. 'Desire is a relation to being to lack. The lack is the lack of properly speaking. It is not the lack of this or that, but lack of being whereby the being exists.'
Lacan states that until an infant sees themselves in the mirror for the first time, they see themselves as individual, separate body parts. Once they see their whole self in the mirror, the sense of self and identity is created. They become one dimensional. This realisation can be unsettling as the image the child sees in the mirror may not even match up how they felt inside or how they thought they looked. Lacan states that due to this, individuals will strive to always be more like the mirror's reflection of themselves. Due to this, ourselves are misunderstood and people continue to misunderstand each other. We will always maintain our appearance to avoid allowing the outside world to know of our chaotic internal selves.
This is similar to the Freudian approach of the 'Id' acting on the hedonistic lifestyle whereas the super ego acts on the moral principles and what lack relates to is the ego which is in between. From a Freudian approach, the lack of hedonistic features strive us to act on moral principles and vice versa.

There are 3 lacks:

1. Symbolic castration and its object related is the imaginary phallus
2. Imaginary frustration and its object related is the real breast
3. Real privation and its object related is the symbolic phallus

The 3 corresponding agents of the lacks are the real father, the symbolic mother and the imaginary father. Of these three forms of lack, castration is the most important from the perspective of the cure.