Assigned to the Atharvaveda, the Māṇḍūkya Upanishad consists of twelve terse mantras which discuss the problem of ultimate reality. Since the ultimate reality transcends the categories of time, space, and causation, it is incomprehensible to the human mind. To make the subject of ultimate reality comprehensible, the Māṇḍūkya Upanishad uses the syllable “Aum” (the aksara OM) to examine the divine principle on which the cosmos has been created. The Upanishad begins with the declaration: “The syllable OM is all this [whole of cosmos]. To explain further: what is called past, present and future is all just OM. Whatever else there is, beyond the three times, that too is all just OM.” This means that the four dimensions—past, present, future, and the fourth dimension which transcends time—are subsumed in OM.
The second verse of the Upanishad says: “All this is brahman. The self is brahman. The self has four feet.” In the third, fourth, fifth, and sixth verses, the four feet of the self are described as the four states of consciousness: wakeful state, dream state, deep sleep state; and the state of being radiant with knowledge of the inner self. In verse seven, further explanation is given of the radiant fourth state of consciousness. The verses eight to twelve provide an insight into the fourfold etymological root of Aum, which consists of four symbols: A, U, M, and the fourth being free of all elements. The verse nine says that the first symbol “A” represents the waking state, and denotes the aspect of obtaining or attaining one’s desires. The verse ten says that the second symbol “U” is related to the term “utkarsa” which means rising up—the one who knows this ensures that no one in his family is lacking in the knowledge of the brahman. The verse eleven says that the third symbol “M” denotes creating and erecting or merging and dissolving—to know this is to create all this and dissolve all this. The last verse in the Upanishad, verse twelve, talks about the fourth, element-less symbol, which is inviolate, gracious, and without duality (advaita).
The Māṇḍūkya Upanishad relates the symbols A, U, M, and the one that is element-less with the four types of soul: “A” denotes the Vaisvanara soul, the experiencer of gross things; “U” denotes the Taijasa soul, the experiencer of the subtle; “M” denotes the Prajna soul, the experiencer of creating and erecting or merging and dissolving; the element-less symbol denotes the Turiya soul, which is the supreme self. Through its depictions of the four modes of consciousness and the four types of souls, the Upanishad shows that the fourth type of consciousness and soul is the basis for the other three types. If Prajna is taken as a representation of Isvara (the Supreme God), then it can be inferred that the supreme mind which dwells in the deep sleep stage is responsible for keeping all things in a condition of becoming.
The brevity of the Māṇḍūkya Upanishad makes it difficult for readers to comprehend its philosophical wisdom. To explain its doctrine, Gudapada, the teacher of Sankaracharya’s teacher, wrote the Māṇḍukya Kārikā, which consists of 215 verses, divided into four chapters: Chapter One (29 verses), “Agama Prakarana (Traditional Doctrine); Chapter Two (38 verses), “Vaitathya Prakarana” (The Illusoriness of Self Experiences); Chapter Three (48 verses). “Advaita Prakarana” (Non-duality); Chapter Four (100 verses), “Alatasanti Prakarana” (The Quenching of the Firebrand). The first chapter examines the problem of reality as described in the Vedas and the next three chapters expound the same truth by means of reason. The Māṇḍūkya Upanishad and the Māṇḍukya Kārikā are the classical texts for the Advaita (non-dualist) Vedanta school of Hinduism. In his commentary on Gudapada’s Kārikā, Sankaracharya says that the Māṇḍūkya Upanishad contains the essence of all the Upanishads; it represents the totality of the human experience. The appeal and influence of the Māṇḍukya Upanishad has undoubtedly been enhanced by Gudapada’s Kārikā and Sankaracharya’s commentary on the Kārikā.
It is impossible to accurately date the Māṇḍūkya Upanishad, but some scholars believe that it could have been developed before Buddha or in the time of Buddha—which means that it can be placed in the fifth or sixth century BC. There is controversy regarding Gudapada dates too. It is generally accepted that he flourished in the sixth century AD; this date has been proposed by scholars like S N Das Gupta who posit that since Gudapada has mentioned the word “Buddha” in his texts several times, he must be a Buddhist thinker and must belong to a period after the Buddhist teachers Asvagosa, Nagarjuna, Asanga and Vasubandhu. On this basis Sankaracharya is placed in the eighth century AD. But other scholars place Gudapada in the third century BC, and Sankaracharya in the second century BC. Swami Nikhiananda is of the view that when Gudapada uses the word “Buddha,” he is not referring to the traditional founder of Buddhism, rather, he is talking about the knower of truth which is one of the meanings of the word “Buddha”. Nikhilananda holds that there is nothing in the Kārikā to connect Gudapada with Buddhism—moreover, Sankaracharya in his commentary on the Kārikā, notes that Buddha has not taught that the essence of ultimate reality is non-dual.
The content of an Upanishad is not to be judged by its title, but the word “Māṇḍūkya” (Sanskrit: मण्डूक) has some interesting flavors which are worth examining. This Sanskrit word can have several meanings like “frog,” “a certain breed of horse,” and “spiritual distress,” but many scholars are of the view that “frog” is the right etymological root for the word “Māṇḍūkya” in the title of the Upanishad. So for what possible reason did the sages who compiled the Māṇḍūkya Upanishad paid such a great homage to the frog?
The unique thing about the frogs is that they hibernate in mud and water pools for several months every year. During this period they remain in isolation, far from other creatures, they do not indulge in any physical activity. Since all their bodily desires are suppressed, they do not eat or drink, they do not lust for companionship, even their breathing is controlled. When their period of hibernation is over, they emerge from the secluded space and start croaking their message. The ancient sages equated hibernation of the frogs with a life of seclusion and contemplation. They believed that human beings can minimize their material desires and the actions of their body and turn their focus on developing wisdom and spiritual values. A sage is typically a man who departs from the crowded towns and villages and goes to the secluded mountains where he leads a frugal life and studies, meditates, and develops his philosophical thoughts—in a sense, such sages are hibernating. When they achieve enlightenment, they return to the world and share their wisdom with the deserving ones.
The principle teaching of Māṇḍūkya Upanishad is that wisdom can be achieved through focussed and undistracted action—but to achieve this kind of mindset, a certain level of seclusion is necessary. Pranava, which is the exercise of meditating on the sacred syllable Aum (OM), is recommended by the Upanishad. Gudapada and Sankaracharya have preached that enlightenment can be achieved by following the teachings of the Māṇḍūkya Upanishad—the stage of enlightenment is called “turiya”, this is the stage when the mind transcends the world of material things and becomes one with the brahman, the radiant prime author of the universe.