Mandukya Upanishad, verse 4

स्वप्नस्थानोऽन्तः प्रज्ञाः सप्ताङ्ग एकोनविंशतिमुखः प्रविविक्तभुक्तैजसो द्वितीयः पादः ॥ ४ ॥

svapnasthāno'ntaḥ prajñāḥ saptāṅga ekonaviṃśatimukhaḥ praviviktabhuktaijaso dvitīyaḥ pādaḥ || 4 ||

4. The second quarter (Pāda) is the Taijasa whose sphere (of activity) is the dream, who is conscious of internal objects, who has seven limbs and nineteen mouths and who experiences the subtle objects.

Shankara Bhashya (commentary)

He is called the Svapnasthāna because the dream (state) is his (Taijasa) sphere. Waking consciousness, being associated as it is with many means,¹ and appearing² conscious of objects as if external, though (in reality) they are nothing but states³ of mind, leaves in the mind corresponding⁴ impressions. That the mind (in dream) without⁵ any of the external means, but possessed of the impressions left on it by the waking consciousness, like⁶ a piece of canvas⁷ with the pictures painted on it, experiences the dream state also as if it were like the waking, is due to its being under the influence of ignorance, desire and their action.⁸ Thus⁹ it is said, “(And when he falls asleep) then after having taken away with him (portion of the) impressions from the world during the waking state (destroying and building up again, he experiences dream by his own light)” (Bṛhadāraṇyaka Upaniṣad, 4. 3. 9). Similarly the Atharvana, after introducing the subject with “(all the senses) become one in the highest¹⁰ Deva, the mind,” continues “There the god (mind) enjoys in dream greatness”¹¹ (Praśna Upaniṣad). From¹² the standpoint of the sense-organs, the mind is internal. He (the Taijasa) is called the Antaḥprajña or conscious of the internal because his consciousness in dream becomes aware of the mental states, which are impressions left by the previous waking state. He is called the Taijasa because he appears as the subject though this (dream) consciousness is without any (gross) object and is of the nature of the essence of light. The Viśva (the subject of the waking state) experiences consciousness associated with gross external objects; whereas, here (in the dream state), the object of experience is consciousness consisting of Vāsanās (the impressions of past experience). Therefore this experience is called the experience¹³ of the subtle. The rest is common (with the previous Śruti). This Taijasa is the second quarter (of Ātmarn).

Anandagiri Tika (glossary)

¹ Means.—Subject-object relationship, agency, instrumentality, etc.

² Appearing—According to Vedānta, external objects, perceived by the sense-organs, have no absolute reality. They appear as real on account of Avidyā. Their reality cannot be proved for the simple reason that they become non-existent when their essential character is enquired into.

³ States of mind— External objects are nothing but mental existents produced by Avidyā. There are no such independent external entities as objects; they are but creations of the mind. In fact we are not conscious of any external objects independent of the mind. We take our mental creations to be such objects. Again those who seek for the cause of these mental creations or ideas, which we think we see as external objects, are led into a logical regressus. This causal chain leads nowhere. It will be shown later on that the whole idea of cause and effect is unreal.

⁴ Corresponding, etc.—that is, like those experienced in the waking state. These impressions are subsequently reproduced in the form of dream-objects.

⁵ Without any, etc.—It is because in dream no other separate entity than the mind of the dreamer, is present.

⁶ Like a piece, etc.—Dream experiences appear as real as the experiences of the waking state.

⁷ Like a piece of canvas, etc.—The picture painted on a piece of canvas appears to possess various dimensions though, in reality, the picture is on a plane surface. Similarly, dream-experiences, though really states of mind, appear to be characterized by the-presence of externality and intemality.

⁸ Action—The word “Karma” is used in Vedānta in more senses than one. “Karma” primarily means “action It also signifies the destiny forged by one in one’s past incarnation or present: the store of tendencies, impulses, characteristics and habits,, which determine one’s future èmbodiment and environment. Another meaning of “Karma”, often used in reference to one’s caste or position in life, is ritual, the course of conduct, which one ought to follow in pursuance of the tendencies acquired in the past, with a view to work them out. The meaning of the word, here, is the tendencies generated in the mind by the activities of the waking state. Avidyā gives rise to Kāma or desire, and this in its turn, impels a man to action.

⁹ Thus, etc.—The causal relation between the waking and the dream states is sought to be established here on scriptural authority.

¹⁰ Highest, etc.—it is because in the dream state the Jīva is associated with the Upādhi of mind.

¹¹ Greatness—The Jīva in sleep, characterized by darkness, possesses the light by means of which the subject-object relationship is seen. The greatness of mind consists in the fact that in dream, it can transform itself into knowledge, act of knowing and the object of knowledge.

¹² From the standpoint of— From the standpoint of the waking state alone when the sense-organs are active, one can review the dream experiences and thus come to know the internal activity of the mind which acts in the dream state independently of the sense-organs of the waking state.

¹³ Experience of the subtle—The experiences of waking and dream states are of the same nature; for in both the states the perceiver is aware only of his mental states which are not related to any external objects, as they are non-existent. From the standpoint of dream, dream objects are as gross and material as those experienced in the waking state. From the view-point of the waking state alone, one may infer that the dream objects are subtle, that is, composed of mere impressions of the waking state, inasmuch as in the dream state no external (that is, gross) object exists at all.