But what these Asuras or (evil) spirits really are may be read easily from the texts.  The gods are the spirits of light; the Asuras are the spirits of darkness.  Therewith is indissolubly connected the idea that sin and darkness are of the same nature.  So one reads that when the sun rises it frees itself ‘from darkness, from sin,’ as a snake from its slough (ib. II. 3.  I. 6).  And in another passage it is said that darkness and illusion were given to the Asuras as their portion by the Father-god (ib. II. 4. 2. 5).  With this may be compared also the frequent grouping of The Asuras or Rakshas with darkness (e.g., ib. III. 8. 2. 15; IV. 3. 4. 21).  As to the nature of the gods the evidence is contradictory.  Both gods and evil spirits were originally soulless and mortal.  Agni (Fire) alone was immortal, and it was only through him that the others continued to live.  They became immortal by putting in their inmost being the holy (immortal) fire (ib. II. 2. 2. 8).  On the other hand, it is said that Agni was originally without brightness; and Indra, identified with the sun, was originally dark (ib. IV. 5.4.3; III. 4. 2. 15).  The belief in an originally human condition of the gods (even the Father-god was originally mortal) is exemplified in a further passage, where it is said that the gods used to live on earth, but they grew tired of man’s endless petitions and fled; also in another place, where it is stated that the gods used to drink together with men visibly, but now they do so invisibly (ib.  II. 3. 4. 4; III. 6. 2. 26).  How did such gods obtain their supremacy?  The answer is simple, ‘by sacrifice’ (Cat.  Br.  III. 1. 4. 3; [=A]it.  Br.  II.  I. I).  So now they live by sacrifice:  ’The sun would not rise if the priest did not make sacrifice’ (Cat.  Br.  II. 3. 1. 5).  Even the order of things would change if the order of ceremonial were varied:  Night would be eternal if the priests did so and so; the months would not pass, one following the other, if the priests walked out or entered together, etc. (ib. IV. 3. 1. 9-10).  It is by a knowledge of the Vedas that one conquers all things, and the sacrifice is part and application of this knowledge, which in one passage is thus reconditely subdivided:  ’Threefold is knowledge, the Rig Veda, the Yajur Veda, and the S[=a]ma Veda.[15] The Rig Veda, i.e., the verses sung, are the earth; the Yajus is air; the S[=a]man is the sky.  He conquers earth, air, and sky respectively by these three Vedas.  The Rik and S[=a]man are Indra and are speech; the Yajus is Vishnu and mind’ (ib. IV. 6. 7. 1 ff.).  An item follows that touches on a modern philosophical question.  Apropos of speech and mind:  ’Where speech (alone) existed everything was accomplished and known; but where mind (alone) existed nothing was accomplished or known’ (ib. I. 4. 4. 3-4, 7).  Mind and speech are male and female, and as yoke-fellows