The Supreme Spirit.
General information
ब्रह्मन् is the root cause of this universe. From ब्रह्मन् originated आकाश (sky). From sky came air, from air came अग्नि and from अग्नि came water and from water was born this earth. (Chapter 377, Agni Purāṇa)
General characteristics
ब्रह्मन् is such that he who says he knows it does not know it and he who says he does not know it, knows it. It is beyond the experiences of time and space. The chief attributes of ब्रह्मन् are सत्, चित् and आनन्द . सत् means existence, the really existent truth. The one and undivided existence. There are pandits who say that it was undivided, नास्तित्व (nonexistence) that was at the beginning of the Universe. Since nothing can be born from 'nothing' the world should have started from अस्तित्व (existence). There is a saying in ऋग्वेद explaining the position thus:--"There was neither अस्तित्व nor नास्तित्व (existence or non-existence) at the beginning." It is a matter to ponder how strongly conscious was the ऋषि who made the above statement about the परब्रह्मन्ऽस् निर्गुणत्व (devoid of attributes) and how clearly he tries to make it understandable to those who have not experienced the idea.
चित् means knowledge, splendour, consciousness. आनन्द means bliss. Paul Deussen writes that the ancient उपनिषद्स् do not include in the definition of ब्रह्मन् the term 'ānanda'.
The two forms of ब्रह्मन्
ब्रह्मन् has two forms- परब्रह्मन् and अपरब्रह्मन् . परब्रह्मन् is अमूर्त (formless, incorporeal) and अपरब्रह्मन् is मूर्त (embodied, corporeal). The अमूर्त ब्रह्मन् is known by such names as परब्रह्मन् , परमात्मा and निर्गुणब्रह्मन् . The corporeal or material ब्रह्मन् is अपरब्रह्मन् and thus this whole world is अपरब्रह्मन् .
The उपनिषद्स् about ब्रह्मन्
अशब्दमस्पर्शमरूपमव्ययं तथास्रसं नित्यमगन्धवच्च यत् । अनाद्यनन्तं महतः परं ध्रुवं विचार्य तन्मृत्युमुखात् प्रमुच्यते ॥ (कठोपनिषद्)
(With no sound, touch, form, taste or smell, with neither beginning nor end
ब्रह्मन् is imperishable).
न तत्र चक्षुर्गच्छति न वाक् गच्छति नो मनो न विद्मो न विजानीमो यथैतदनुशिष्यते । अन्यदेव तद्विदितादथो अविदितादधि इति शुश्रुम पूर्वेषां ये नस्तद्व्याचचक्षिरे। (मुण्डकोपनिषद्)
(No eye goes there, no word goes there, no mind, no intelligence--we do not see it, we cannot describe it-you cannot imagine it nor can you understand it--It is distinct from the known and above the unknown. We have heard it spoken thus).
यस्यामतं तस्य मतं मतं यस्य न वेद सः । अविज्ञातं विजानतां विज्ञातम् अविजानताम्। ॥
(Kenopaniṣad) (He understands It who comprehends It not; and he understands It not who feels he has understood. It is the unknown to those who have acquired real knowledge while it is the known to those who are ignorant of true knowledge).
यत् चक्षुषा न पश्यति येन चक्षूंषि पश्यति । तदेव ब्रह्म त्वं विद्धि नेदं यदिदमुपासते। ॥
(Kenopaniṣad). (That which is not seen by the eye but that by which the eyes are able to see--That alone is Brahman and not that which people do worship here, do know that).
यतो वाचो निवर्तन्ते अप्राप्य मनसा सह।
(Taittirīya Upaniṣad). अविज्ञातं विजानतां विज्ञातम् अविजानताम्।
(Kenopaniṣad) (It is unknown to people who think they know but known to those who did not profess to know it).
नैव वाचा न मनसा प्राप्तुं शक्यो न चक्षुषा । अस्तीति ब्रुवतोस्न्यत्र कथं तदुपलक्ष्यते। ॥
(Kaṭhopaniṣad) . (It is not possible to reach it by speech, mind or the eyes. How is it to be identified; or described?)-
दिग्देशगुणादिफलभेदशून्यं hi
परमार्थ-सत् tad
अद्वयं ब्रह्म mandabuddhīnām asadiva pratibhāti.
(Śaṅkarācārya). The sublime Truth (Brahman) is beyond time, place and attributes. Brahman is one (not two) and it is Sat (existent) but for the dull-witted, ignorant people it is Asat (non-existent).
सत्यमेवोपासते, तदेतत् त्र्यक्षरं सत्यमिति; स इत्येकमक्षरम्, त्य इत्येक। मक्षरम्, प्रथमोत्तमे अक्षरे सत्यम् मध्यतो अनृतं तदेततमृतमुभयतः सत्येन परिगृहीतं सत्यभूयमेव भवति।
(Bṛhadāraṇyaka). Kohamasmīti satyamiti brūyāt kiṃ tad yat Satyamiti yadanyad devebhyaśca prāṇebhyaśca / Tatsadatha yaddevāśca prāṇāśca tad utadeṬayāpicābhivyāhriyate satyamitye Tadāpatitaṃ sarvamidam
(Kauṣītaki Brāhmaṇa). इदं सर्वं खलु ब्रह्म इति शान्त उपासीत अन्तर्हृदये एष मे आत्मा मनोमयः प्राणशरीरः भारूपः सत्यसङ्कल्पः आकाशात्मा सर्वकर्मा सर्वकामः सर्वगन्धः सर्वमिदमभ्यत्ति . (chāndogya) .