of good is difficult yet eternal, while Ignorance/Delusion and the pursuit of the pleasant is easy yet transient. Knowledge requires effort, and often not comprehended by man even when he reads it or hears it or by internal argument. The pursuit of Knowledge and the good, can be taught, learnt and thus realized. A similar discussion and distinction between the pleasant and the beneficial is found in ancient Greek philosophy, such as in Phaedrus by Plato. Atman exists, the theory of Yoga and the essence of Vedas - Second Valli Katha Upanishad, in verses 1.2.12 asserts Atman – Self – exists, though it is invisible and full of mystery. It is ancient, and recognizable by Yoga (meditation on one's self), states Katha Upanishad. This is one of the earliest mentions of Yoga in ancient Sanskrit literature, in the context of Self-development and meditation. In verses 1.2.14 through 1.2.22, the Katha Upanishad asserts that the essence of Veda is to make man liberated and free, look past what has happened and what has not happened, free from the past and the future, refocus his attention past Ignorance to Knowledge, to the means of blissful existence beyond joy and sorrow. This is achievable through realization of Atman-Brahman, asserts Katha Upanishad, and this essence is reminded in the Vedas through the word Om (, Aum), state verses 1.2.15-1.2.16. That syllable, Aum, is in Brahman, means Brahman, means the Highest, means the Blissful within. Yama is the spokesman in the second Valli of the Katha Upanishad. He asserts that man must not fear anyone or anything (not even death) as the true essence of man (Atman) is neither born nor dies; he is eternal, he is Brahman. These passages have been widely studied, and inspired Emerson among others: In final verses of the second Valli, the Katha Upanishad asserts that Atman-knowledge, or Self-realization, is not attained by instruction, not arguments nor reasoning from scriptures. It is comprehended by oneself through meditation and introspection. It is not attained by those who do not abstain from misconduct, not those who are restless nor composed, not those whose mind is not calm and tranquil, but only those who live ethically, are composed, tranquil, internally peaceful, search within and examine their own nature. Similar ideas are repeated in the Mundaka Upanishad in chapter 3.2, another classic ancient scripture of Hinduism. The parable of the chariot - Third Valli