Māyā () is the veiling of the true, unitary Self. The Kirtimukha mask, like Māyā hiding Reality, is present in all of us. Spiritual aspirants are reminded of this stark reality and warned about the power of this hidden mind to take over and overwhelm us. To remind us of this fact, his image is present everywhere in Hindu temples: -in the gopurams, on the ramparts and even in the prabhai (arch) above the idol in the garbha-griha (sanctum sanctorium). 

 In his book "Myths to Live By", Joseph Campbell narrates this story about Kirtimukha from Hindu mythology  (Siva Puranam), that is highly symbolic of the self-destructive nature of the unbridled ego-self  in us.

    "Let me recount now a really marvelous Hindu legend to this point, from the infinitely rich mythology of the god Shiva and his glorious world-goddess Parvati. The occasion was of a time when there came before this great divinity an audacious demon who had just overthrown the ruling gods of the world and now came to confront the highest of all with a non-negotiable demand, namely, that the god should hand over his goddess to the demon. Well, what Shiva did in reply was simply to open that mystic third eye in the middle of his forehead, and puff! a lightning bolt hit the earth, and there was suddenly there a second demon, even larger than the first. He was a great lean thing with a lion-like head, hair waving to the quarters of the world, and his nature was sheer hunger. He had been brought into being to eat up the first, and was clearly fit to do so. The first thought: "So what do I do now?" and with a very fortunate decision threw himself upon Shiva's mercy.

Now it is a well-known theological rule that when you throw yourself on a god's mercy the god cannot refuse to protect you; and so Shiva had now to guard and protect the first demon from the second. Which left the second, however, without meat to quell his hunger and in anguish he asked Shiva, "Whom, then, do I eat?" to which the god replied, "Well, let's see: why not eat yourself?"

And with that, no sooner said than begun. Commencing with his feet, teeth chopping away, that grim phenomenon came right on up the line, through his own belly, on up through his chest and neck, until all that remained was a face. And the god, thereupon, was enchanted. For here at last was a perfect image of the monstrous thing that is life, which lives on itself. And to that sun-like mask, which was now all that was left of that lion-like vision of hunger, Shiva said, exulting, "I shall call you Face of Glory, 'Kirttimukha', and you shall shine above the doors to all my temples. No one who refuses to honor and worship you will come ever to knowledge of me." 

The obvious lesson of all of which is that the first step to the knowledge of the highest divine symbol of the wonder and mystery of life is in the recognition of the monstrous nature of life and its glory in that character: the realization that this is just how it is and that it cannot and will not be changed. Those who think�and their name is legion�that they know how the universe could have been better than it is, how it would have been had they created it, without pain, without sorrow, without time, without life, are unfit for illumination. Or those who think�as do many� "Let me first correct society, then get around to my­self" are barred from even the outer gate of the mansion of God's peace. 

All societies are evil, sorrowful, inequitable; and so they will always be. So if you really want to help this world, what you will have to teach is how to live in it. And that, no one can do who has not himself learned how to live in it in the joyful sorrow and sorrowful joy of the knowledge of life as it is. That is the meaning of the monstrous Kirtimukha, 'Face of Glory', over the entrances to the sanctuaries of the god of yoga, whose bride is the goddess of life. No one can know this god and goddess who will not bow to that mask in reverence and pass humbly through."

My thoughts on Kirtimukha:

Kirtimukha is represented as a face personifying ferocity with protruding eye-balls, stout horns, wide opened mouth suggesting a roar and canine teeth protruding out of it.. The terrifying face of Kirtimukha stares at us through his fierce protruding eyes everywhere in our temples -- on the ramparts, the Gopurams and even from the center of the arch (prabhai) over the idol that we worship inside the Sanctum Sanctorium (garbha gruha). The face is perhaps symbolic of our thoughtless pursuit of worldly possessions and pleasures, even at the risk of damaging and destroying ourselves.

The intention behind placing this figure ubiquitously in our temples  may be to remind us constantly : 

"You know this face very well; it is the likeness of your own mind with its unbridled passions and aggressive desires.  Like this demon, you too have a voracious, unlimited appetite for wealth, power, glory and the pursuit of pleasure.  You have become acquisitive, arrogant and mindless even like the demon's nature.  You have to be truly aware of this and of the raging fire residing in you which is consuming you.  Put out this fire before it is too late.  Only then can you really see the Lord in the idol whom you have come to worship, and realize true happiness and Bliss."

The warning that Kirtimukha is active in us and deluding us is implied in one of Bhartruhari's famous shatakams:

Be Aware:

The pleasures of life are not consumed by us;
it is we that are consumed by the pleasures.

A penance is not performed by us;
we merely suffer the pain of the penance.

Time has not gone by ;
We have been carried away by time 
(without our consent and away from our goals).

Our longings have not been fulfilled or exhausted;
we have been wasted by our longings

Author Cordelia Fine in a recent Book "A Mind of its Own: How Your Brain Distorts and Deceives" has characterised the general nature of the human mind as " Vain, immoral, bigoted: this is your brain in action" and advised that "the path to overcoming stereotypes and other distortions of the brain may be gained through self-awareness." A Book-Review from the Publishers Weekly (http://www.amazon.com/Mind-its-Own-Distorts-Deceives/dp/product-description/0393062139) is reproduced below: 

"Vain, immoral, bigoted: this is your brain in action -- according to Cordelia Fine, a research associate at the Centre for Applied Philosophy and Public Ethics at Australian National University. She documents a wealth of surprising information about the brain in this readable account that adopts a good-humored tone about the brain's failings without under-estimating the damage they do. The brain, she shows, distorts reality in order to save us from the ego-destroying effects of failure and pessimism. For example, an optimist who fails at something edits the truth by blaming others for the failure and then takes complete credit for any successes. The brain also routinely disapproves of other people's behavior (how could he do that?), while at the same time interpreting one's own actions in the best possible light (I would never do that!). The brain also projects stereotypes onto others that reflect prejudicial beliefs rather than objective reality. Despite the firm hold these distortions have on our brains, Fine is not a pessimist. The path to overcoming stereotypes and other distortions of the brain, she says, may be gained through self-awareness and knowledge provided by experimental psychology, a field that explores and exposes unconscious mental influences.

See also Controlling the reptilian Brain

In this context, it is instructive to read the following extract from a talk given by Sri Amma on temples:

Sri Amma (Sri Mathioli Saraswathy) : 

"The basic tenet of Hinduism is that in every thing that exists - from the atom to the universe - God resides with the qualities of Sat, Chith and Anandam: Existence, Consciousness and Bliss. The principal reason for the construction of the temple is to reach the goal of Self-realization. When we ask of a person: "Who are you?" the reply will emphasize the person's name, fame and possessions.  But all these are merely attributes of the body. Removing this false identification of the Self with the physical body and teaching the truth: "You are not your body; you are not your knowledge, qualifications etc; you are the soul that is beyond all this" is the main purpose of establishing a temple.

The heart is where our life resides. In the same manner, the Garbhagruha or the Sanctum Sanctorium is where the Spirit is and hence it is known as the Moolasthanam. The idol of the deity in the Moolasthanam is established after Yantra Prathishta.  In common parlance, the Yantra is like the engine without which the vehicle will not move.  In the same manner, when the deity is installed without the consecration ceremony of Yanthra Prathishtaanam, the devotees will be unable to receive the Grace of the Lord and the temple itself will not attract devotees.

God's Grace is represented in the form of the idol in the Garbhagruham and in the form of a symbol in the Gopuram of the temple. As we approach and enter the temple, these are the few thoughts that we should entertain in our minds: On seeing the Gopuram, the devotee should remind himself/herself: " I am not this body, I am the Soul within."  With this thought, we will be able to perceive others also in the same manner. As we pass the Gopuram and enter the temple, there are many other enclosures with doors to enter. Our body is also like these many walls that hide the soul within. Understanding this will help us to realize the truth that we are the soul within, not the body outside. The next place we come to is the Bali Peetam, the sacrificial altar. This reminds us of the state in which the soul within is placed.  As the devotee with faith in the statement: "I am not the body, I am the soul" enters through the Gopuram Gate, he/she should shed on the Bali Peetam all his/her animal qualities of Kama (desire), Krodha (anger), Lobha (Avarice), Moha (delusion), Madha (Pride), and Maatsaryam (Jealousy) and prostrate before the Bali Peetam symbolically to realize in the mind the pure state of the soul within.

An artist's interpretation of Kirtimukha as a mascot of Hope:  http://www.hinduonnet.com/folio/fo0104/01040380.htm ) 

The painter Baiju Parthan, who also makes web-based works, articulates the same crippling historical simultaneity in "Artefact" (Mixed Media, 2000). The picture frame is divided into two vertical halves: to the right, we see the Wodeyar Prince of Mysore presiding over a ceremony replete with pomp, splendour and the royal parasol; while to the left, we see faint images of a bag and stick belonging to a victim of the 1999 Orissa super-cyclone. The relationship between these contrasting images, accessed by Parthan from the 1999 year-end Special Issue of Outlook magazine, is self-explanatory.

The more conundrumatic details in the painting are four word-seals, marked BUILDS, JOINS, FIXES, SEALS, pasted on the painting. These seals are slogans associated with a particular brand of industrial product, the M-SEAL epoxy putty employed to fix breakages and leaks. Parthan reveals the quintessential Third World predicament by employing product promo-slogans that seem to echo the unfulfilled Nehruvian idyll of a strong nation-state created through colossal projects, big dams and homegrown large-scale industries.

Fifty years down the line, the big dams have become ecological disasters and the homegrown large-scale industries are being swept aside by transnational corporations. As the cyclone victims become ciphers in the picture frame, we see above the two contrasts, what I may call an India Gate of contrasting realities: a kirti-mukha. Parthan has chosen the kirti-mukha as a mascot of hope, for it embodies the primordial myth of the constant self-renewal of the universe, which sustains itself by devouring itself. This image points to the possibilities of change and replenishment that can stem the growing inequalities in a nation state. By weaving different strands, that of the classical (the kirti-mukha), the industrial (the M-Seal), the mock-regal (the Wodeyar ruler) and the subaltern (the super-cyclone victim), Parthan renders the ancient myth a contemporary index, and reveals the contemporary situation as a perennial predicament.

Extracts from http://www.picatype.com/dig/dk2/dk2aa01.htm :(this link is not working now)

DECORATIVE MOTIFS IN VIJAYNAGAR SCULPTURES by Rajaram Hegde,
Department of History and Archaeology, Kuvempu University, Karnataka

Foliage motifs provided a greater scope for artists imagination. The motif was rendered into different shapes according to the requirement of the space. Foliage is often shown, issuing from the mouths of mythical creatures like Makara, yali and kirtimukha. A variety of animal forms which are usually denoted as yali or vyala are to be seen prominently in Vijayanagara decorative motifs. They are usually leonine in their physical features. Their face is usually depicted either as elephantine (Fig. 34,37) or as a stylised lion's head (Fig. 39, 41) 13(Dhakey: op. cit:16). Vijayanagara sculptures represent the following varieties of vyalas: (1) Elephant faced (gaja-vyala) (2) Lion or kirtimukha faced (simha-vyala) (3) Horse faced (asva-vyala) (4) Human faced (nr-vyala). (5) Dog faced (svana-vyala). Perhaps, no other motif is so widely used as the kirtimukha (Fig. 11, 12, 22, 47).

Kirtimukhas are shown at the top of aureole, kapotas, dormer arches etc. They are used in any decoration where the artist wants to show strings, foliage or festoons issuing from its mouth. Kirtimukha is represented as a face personifying ferocity with protruding eye-balls, stout horns, wide opened mouth suggesting a roar and canine teeth protruding out of it. This particular treatment was almost common to any ferocious face as we see similar faces on Nrsimha's icons, leographs, etc 14(Dhavalikar 1982:86). 'The kirtimukhas, literally the face of 'glory' or 'fame' became an integral part of the Indian decorative tradition in the early historic period itself 26. Coomaraswamy traces their probable origin in the Greek heads 27(Coomaraswamy 1971:49, Dhavalikar op.cit.,90).

The myth of kirtimukha suggests it was symbolic of the destructive force of Siva, used to devour the demons28(Zimmer: 1946:322-31, 1990:175-184). Thus in Medieval canonic tradition, kirtimukha heralded the glory of divine power which was the source of creation and destruction 29(Agrawala 1956-57:94). 14. Davalikar M.K., (1982:86) Kirtimukha was also known as Simha-mukha in literature. During the medieval period, Kirtimukhas invariably assume the form of a stylised lion's face in Indian art. Such stylised lion's face can be traced back to the Persian lion-faces which for the first time in India appear on the Mauryan pillar capitals.

During the medieval period, this face commonly appears on the ferocious animal figures. 26. Kirtimukha is also known as Grasamukha in Western India, Rahumukha in Eastern India, 'Kala' in South East Asian Countries. It is also known as Makara Vakstra, Simha-mukha etc. These terms signify the historical development of its symbolism. 27. Coomaraswamy A.K. (1971:49) notices the presence of similar decorative motifs in Scythian, Helenic, Chinese art traditions. Gorgons heads were the terrific faces to ward off the enemy and such faces were carved on the Greek forts, palaces, temples and such edifices.

Earliest Kirtimukhas in India are demonic in forms. Thus a Hellenic origin is possible (See. Dhavalikar M.K. op. cit., 90). 28. Zimmer Heinrich. (1990: 175-184) opines that Kirtimukha was Rahu who had no body. Stella Kramrisch also identifies Kirtimukha with Rahu who devours sun, and Rahu had no body according to myths (1946: 322-31). 29. Traditionally Kirtimukhas are believed to be warding the edifices off the evil and destroyers. V.S. Agrawala concludes that the term Kirti: denotes an excavated chamber, Kirtimukha being its fa�ade. (1956-57; p.94).

Whatever might be the etymological derivations, Kirtimukha assumed a magical significance of warding off the evil, thus an auspicious motif in architecture