Dirghatamas (Sanskrit: दीर्घतमस्, romanized: Dīrghatamas) was an ancient Indian Brahmin sage well known for his philosophical verses in the Rigveda. He was the author of Suktas (hymns) 140 to 164 in the first mandala (section) of the Rigveda.^[1]

Dirghatamas was one of the Angirasa rishis, the oldest of the rishi families, and regarded as brother to the rishi Bharadvaja, who is the seer of the sixth Mandala of the Rigveda. Dirghatamas is also the chief predecessor of the Gotama family of rishis that includes Kakshivan, Gautama Maharishi, Nodhas and Vamadeva (seer of the fourth Mandala of the Rigveda), who along with Dirghatamas account for almost 150 of the 1000 hymns of the Rigveda. Anga, Vanga, Kalinga, Pundra and Suhma, Ondra were also the sons of Dirghatamas through Bali’s wife Sudhesana. His own verses occur frequently in many Vedic texts, a few even in the Upanishads.

He was the reputed purohita or chief priest of King Bharata (Aitareya Brahmana VIII.23), one of the earliest kings of the land, after whom India was named as Bharata (the traditional name of the country).

Dīrghatama was son of Raṣṭra.

Bhishma tells the narrative of the birth of Dirghatama in the Mahabharata (Book 1, Adi Parva, CIV):^[2]

"There was in olden days a wise rishi of the name of Utathya. He had a wife of the name Mamata whom he dearly loved. One day Utathya's younger brother Brihaspati, the priest of the celestials, endued with great energy, approached Mamata. The latter, however, told her husband's younger brother—that foremost of eloquent men—that she had conceived from her connection with his elder brother and that, therefore, he should not then seek for the consummation of his wishes. She continued, 'O illustrious Brihaspati, the child that I have conceived has studied in his mother's womb the Vedas with the six Angas, Seed is not lost in vain. How can then this womb of mine afford room for two children at a time? Therefore, it behoveth thee not to seek for the consummation of thy desire at such a time. Thus addressed by her, Brihaspati, though possessed of great wisdom, could not suppress his desire. The child in the womb protested, 'There is no space here for two. O illustrious one, the room is small. I have occupied it first. It behoveth thee not to afflict me.' But Brihaspati without listening to what that child in the womb said, sought the embraces of Mamata possessing the most beautiful pair of eyes. And the illustrious Brihaspati, beholding this, became indignant, and reproached Utathya's child and cursed him, saying, 'Because thou hast spoken to me in the way thou hast at a time of pleasure that is sought after by all creatures, perpetual darkness shall overtake thee.' And from this curse of the illustrious Brihaspati, Utathya's child who was equal unto Brihaspati in energy, was born blind and came to be called Dirghatamas (enveloped in perpetual darkness).

And the wise Dirghatamas, possessed of a knowledge of the Vedas, though born blind, succeeded yet by virtue of his learning, in obtaining for a wife a young and handsome Brahmana maiden of the name of Pradveshi. And having married her, the illustrious Dirghatamas, for the expansion of Utathya's race, begat upon her several children with Gautama Dirghatamas as their eldest.

Dirghatamas was troubled by a bad marriage, unvirtuous sons, and, ultimately, abandonment by other sages and the community.

His children grew up to be covetous and they brought a bad name upon themselves and their father. Ultimately, the sages and students of Dirghatamas abandoned him, for having raised bad men.

Dirgatamas, dejected and utterly alone, sought consolation from his wife, Pradveshi.

He asked her whether she was also upset with him.

She said she was. She said he was not a real husband, neither a protector (Pati) nor a supporter (Bhartri), and she had had to raise the children all alone.

The hurt sage angrily proclaimed in reply that a woman should only marry once in life, regardless of whether her husband is alive or dead.

Enraged, Pradveshi asked her sons to throw their father into the Ganga River. So Gautama and his brother tied Dirghatamas to a raft and threw him into the water.

King Bali happened to be performing ritual ablutions in the holy river at the time, and saw the sage and rescued him.

His life now saved, the sage asked King Bali what he could do in return.

The king asked Dirghatamas to engage in niyoga so that Queen Sudeshna might be able to have children. Dirghatamas assented.

The Queen sent the blind sage a woman of low birth instead, however, and with that woman Dirghatamas sired Kakshivan and ten more sons.

Later, Dirghatamas came to learn that he had been deceived, but Bali ultimately prevailed upon Queen Sudeshna to sire by the sage six sons, bequeathing them their namesake kingdoms of Anga, Vanga, Kalinga, Pundra, Cumbha, and Odra.

Dirghatamas is famous for his paradoxical apothegms.^[3] His mantras are enigmas: "He who knows the father below by what is above, and he who knows the father who is above by what is below is called the poet."

The Asya Vamasya (Rigveda 1.164) is one of the sage's most famous poems. Early scholars (such as Deussen in his Philosophy of the Upanishads) tried to say that the poems of Dirghatamas were of a later nature because of their content, but this has no linguistic support which has been argued by modern Sanskrit scholars (such as Dr. C. Kunhan Raja in his translation of the Asya Vamasya Hymn). The reason that earlier Western scholars believed them to be of a later origin is due to the monist views found there. They believed that early Vedic religion was pantheistic and a monist view of god evolved later in the Upanishads - but the poems of Dirghatamas (1.164.46) which say "there is One Being (Ekam Sat) which is called by many names" proves this idea incorrect.

Some scholars have claimed that the Babylonians invented the zodiac of 360 degrees around 700 BCE, perhaps even earlier, as old as the Rigveda, the oldest Vedic text, there are clear references to a chakra or wheel of 360 spokes placed in the sky. The number 360 and its related numbers like 12, 24, 36, 48, 60, 72, 108, 432 and 720 occur commonly in Vedic symbolism. It is in the hymns of the rishi Dirghatamas (RV I.140 - 164) that we have the clearest such references.

• List of Indian philosophers
• Rigveda

• Gupta, Nolini Kanta. "Seer Poets". Sri Aurobindo Ashram, Pondicherry, 1970.
• Johnson, Willard (1976). "On the ṚG Vedic Riddle of the Two Birds in the Fig Tree (RV 1.164.20-22), and the Discovery of the Vedic Speculative Symposium". Journal of the American Oriental Society. 96 (2): 248–258. doi:10.2307/599827. JSTOR 599827.
• Mahābhārata, Book1, Adi Parva, CIV.
• R̥g-Veda, Sūktas 140 to 164.
• Raja, Dr. C. Kunhan. Asya Vāmasya Hymn, (printed 1956).
• Singh, Prof. Satya Prakash. Life and Vision of the Vedic Seers 2: Dirghatamas. Standard Publishers, New Delhi, 2006.
• Fórizs, László. Dirghatamas In Keréknyomok/Wheeltracks 2019/13: 148-181.
• Apāṁ Napāt, Dirghatamas and Construction of the Brick Altar. Analysis of RV 1.143 In Vedic Investigations, edited by Asko Parpola, Masato Fujii and Stanley Insler, Volume 1, Papers of the 12th World Sanskrit Conference, Motilal Banarsidass, 2016, pp. 97–126, in the homepage of Laszlo Forizs.