Patanjali Yoga Sutra — ब्रह्मचर्यप्रतिष्ठायां वीर्यलाभः॥2.38॥

Brahmacaryapratiṣṭhāyāṃ vīryalābhaḥ॥

When a sādhaka is resolutely committed to continence or chastity, vigor and vitality chase and get established in him

There is a saying: ‘One should be cautious of one’s own thoughts when one is lonely; should be wary of words while amongst people’. When a sādhaka utilizes all the conserved energies to achieve the desired goal of life, it is called ‘Tapas’ (One of the five niyamas). A drain even on sexual energy could take the sādhaka farther away from his spiritual goal. On the other hand, energy conserved could build up vigor and vitality in him which goes a long way in achieving newer heights in his spirituality. Though considered to be a highly debatable topic, no one can deny the fact that men craving only for sense gratification as the main object of life (cārvākas) would see a disastrous end.

Gītā says sexual indulgence as the supreme goal of life leads to complete destruction.

त्रिविधं नरकस्येदं द्वारं नाशनमात्मनः।

कामः क्रोधस्तथा लोभस्तस्मादेतत्त्रयं त्यजेत्॥गीता १६.२१॥

Trividhṃ narakasyedaṃ nāśanamātmanaḥ|

Kāmaḥ krodhastathā lobhastasmādetattrayaṃ tyajet॥Gītā 16.21॥

Lust, anger and greed are the three doorways to hell, as they are destructive of the Self. Hence, should be abandoned.

But Indian philosophy never said that without celibacy spiritual growth is not possible. Many of the great yogis, ṛis were married and lived like gṛhasthas. Vasiṣṭha, Agastya, Kapila etc, were all married. bhagavān Śrīkr̥ṣṇa had more than 16000 wives, yet considered one of the greatest yogis and Brahmacāris. Hence what is imposed is ‘Dharmamārga’ (Righteous way) in sexual pleasure also. In the epic Mahābhārata, we read, dhārmic authorization to have sex with a maharṣi — Niyoga system for the sake of continuity of the dynasty. When Vicitravīrya (grand-father of pāṇḍavas), one of the kings of Kuru dynasty, dies without children, his wives ambikā and ambālikā get children from Vedavyāsa, in a dhārmic way, through Niyoga, for the sake of continuity of dynasty:

1. dṛtarāṣṭra (born blind) and pāṇḍurāja (a born patient of pāṇḍu disease) were born to vyāsa maharṣi for Ambikā and Ambālika respectively.

2. vidura (a great jñāni and author of Viduranīti) was born to Parāśrami a maidservant and vyāsa maharṣi.

Hence, the purpose behind conjugation also decides whether it is illicit (adhārmic) or dhārmic. The subject ‘Brahmacarya’ cannot, therefore, be considered in isolation with many other relevant factors.