So soon however as the idea of Brahmá had attained fixity in the Hindu mind, and simultaneously with it, cast was developed, as we find it (but imperfectly) in the earliest records of Hindu philosophy, the Upanishads.
Thus, cast governs and is antecedent to law, which must bend and adapt itself to cast, as the overruling, intrinsic, unalterable condition of Hinduism, of Hindu life. There is one law, one phase of obligation for the twice-born, another for the Śúdrá. In Manu, cast is not so fully and severely developed: Manu permits to the Bráhmaṇa four wives, of whom one may be a Śúdrá, necessarily permitting, therefore, a transition or quasi-amalgamation between the highest and the lowest in the scale. Yájnavalkya permits this Bráhmaṇical communion with the Kshattriya and Vaisyá, but not with the Śúdrá. Later promulgators of law,[9] restrict the Bráhmaṇa to his own class.
But although cast, once developed, admitted not of change, juridical rules, subservient to cast, might and did progress: civil laws and procedure became more comprehensive and exact, the criminal code more regulated, lenient, and enlightened. And as universally, (for such is human,) breaches and occasional disregard of rules have, silently though surely, worked a change, or caused exceptional accessions to the rules themselves.
The rule of the Śástras, that kingly power should belong to the Kshattriya alone, was, even in the halcyon days of Hindu polity, repeatedly set aside. Chandragupta, a Śúdrá, and his dynasty, held sway over India from 315 to 173 B. C.: afterwards came Bráhmaṇical kings, the Kánwas, from 66 to 21 B. C.: whilst the mighty Gupta kings, from 150 to 280 A. C., were Vaisyás.
The code of Manu presents a disarranged mass of regulations, in so much that some have supposed the disorder to have been designed.
That conclusion, however, is repelled by the comparatively succinct arrangement of Yájnavalkya and other sages. It is more consistent to suppose, that Manu, as originally promulgated, was, from time to time, added to, with an accidental disregard of method.
Áchára, ritual, comprises the distinctive cast-ceremonies, domestic and social usages, rites of purification, of sacrifice.
Vyavahára, may be called the juridical rules, embracing as well substantive law as the procedure and practice of legal tribunals.
Práyaschitta, expiations, are the religious sanctions, or penalties of sin; the divine visitation upon offenders, and the mode in which the sinner may avert, by atonement, the consequences of divine vengeance.