Key Points from each Individual Text  

Plato

Platos cave is based on the idea of Line Analogy of Belief and Illusion, and how further philosophers have replaced the cave with cinema and television. 
It describes the ignorance of our human condition.
Platos cave signifies man ignorances, in the sense that these men are shackled and there knowledge of life is limited to a dark cave and that there slavers torture there minds by playing games and showing them images of how the world is, (depicted by the slavers) and that this is the reality there given is the whole truth.
However, the story tells of what would happen if one man finally leaves, the light of the real world hurts and he has to accustom this change of what the real is, compared to that which is slaver have depicted and told him the world is.  
The man would need to grow accustomed to new things he sees. 
Plato then goes to say that if the man were to return to the cave he fellow prisoners would not believe his truth and subsequently kill him because of their disbelief. 
A key point from Platos cave is understand that "the eyes may be unsighted in two ways, by transition either from light to darkness or from darkness to light, and will recognize that the same thing applies to the mind. 
Further more that all all classes should not be given special welfare and that man should link in the unity of the whole. 

The Simulacrum 

French Sociologist Jean Baudrillard talks about the border between art and reality has utterly vanished as both have collapsed into the universal simulacrum. 
Further more reality has become redundant and has reached hyper reality; meaning images breed incestuously with each other without reference to reality or meaning. 

Visual Culture 

Barthes talks about how the reader is invited to use, value and desire, needs and wants.
There can be no perversion in a world without norms.
The people of the post have set out to undermine the validity between legitimate and illegitimate. 
The project of the post is to replace the dominant (platonic) regime of meaning by a radical anti system which promotes the articulation of difference as an end in itself.
Jean Baudrillard declares that appearances can no longer be said to mask, conceal, distort or falsify reality. 
He says people cease to exist as rational cogitos capable of standing back and totalising  on the basis of our experience. 
Further more the "I" is nothing more than a fictive entity, the subject simply ceases...this is the Post Modern Condition and it takes place in the present tense. 
Marx says that "all that is solid melts into air" and that it has been intensified under contemporary "hypercapitalism". 
New commodities untouched by human hands circulate without any reference to vulgar "primary needs" in a stratosphere of pure exchange. 

Simualcra and Simulation

Pretending or dissumulating leaves the principle of reality intact. Simulation threaten the difference between"true" and "false", the "real" and the "imaginary".
Therefore in order to safeguard the truth and to escape the interrogation posed by simulation, the knowledge that truth, reference, objective cause have ceased to exist. 
Military psychology draws back from Cartesian certainties and hesitates to make the distinction between true and false, between the authentic and symptom and the "produced".
Iconoclasts had metaphysical despair which came from the idea that the image of God didn't conceal anything at all and these images were in essence not images, such as the original model would have made them, but perfect simulacra, forever radiant with their own fascination. 
However, it can be said icon worshippers were modern as knowing that it is dangerous to unmask images since they dissimulate the fact there is nothing behind them. 
Western faith became engaged in the wager on representation that a sign could refer to the depth of meaning, and a sign could be exchanged for meaning.
Representation stems from the principle of the equivalence of the sign and of the real. 
Simulation stems from the utopia of the principle of equivalence. 
The transition from signs that dissumulate something to signs that dissumulate that there is nothing marks a turning point. The first reflects a theology of truth and the second inaugurates the era of simulacra.