'No one shall be vexed twice for the same cause'. Explain the principle and the requirements for its application.

Section 11 of the Civil Procedure Code, 1908 (the Code) deals with the doctrine of Res Judicata. According to the case, S.B. Temple v. V.V.B. Charyulu, (1971) 1 SCJ 215, the doctrine underlines the general principle that 'no one shall be twice vexed for the same cause'. According to this provision, no Court shall try any suit or issue in which the matter has been directly and substantially in issue in a former suit (i.e., suit previously decided) either between the same parties, or between parties under whom they or any of them claim, litigating under the same title in a Court competent to try such subsequent suit or the suit in which such issue has been subsequently raised and finally decided by such Court. It is a pragmatic principle accepted and provided in law that there must be a limit or end to litigation on the same issues. It prevents two different decrees on the same subject. Section 11 says that once a res is judicata, it shall not be adjudged again. The principle applies to suits in Section 11 of the Code; but even where Section 11 does not apply, the principle of res judicata has been applied by Courts for the purpose of giving finality to litigation. For the applicability of the principle of res judicata embodied in Section 11, the following requirements are necessary: The matter directly and substantially in issue in former suit shall also be directly and substantially in issue in later suit. The expression "directly and substantially in issue means an issue alleged by one party and denied or admitted by the other either expressly or by necessary implications (Lonakutty v. Thomman, AIR 1976 SC 1645). In the matter of taxation for levy of municipal taxes, there is no question of res judicata as each year's assessment is final for that year and does not govern latter years (Municipal Corporation v. Madan Mohan, AIR 1976 43). A suit for eviction on reasonable requirement was compromised and the tenant was allowed to continue as tenant for the subsequent suit for ejectment on the ground of reasonable requirement, it was found that some reasonable requirement had been present during the earlier suit. The second suit was not maintainable. The former suit has been decided - former suit means which is decided earlier. The said issue has been heard and finally decided. The issue or the suit itself is heard and finally decided, then it operates as res judicata and not the reasons leading to the decision (Mysore State E. Board v. Bangalore W.C. & S. Mills, AIR 1963 SC 1128). However, no res judicata operates when the points could not have been raised in earlier suit. (Prafulla Chandra v. Surat Roit AIR 1998 Ori. 41). But when a suit has been decided on merits, and the appeal is dismissed on a preliminary point, it amounts to the appeal being heard and finally decided and the decision operates as res judicata (Mukunda Jana v. Kanta Mandal, AIR 1979 NOC 116). Such former suit and the latter are between the same parties or litigation under the same title or persons claiming under parties above (Isher Singh v. Sarwan Singh, AIR 1965 SC 948). In short, this principle applies where an issue which has been raised in a subsequent suit was directly and substantially in issue in a former suit between the same parties and was heard and decided finally. Findings incidentally recorded do not operate as res judicata (Madhvi Amma Bhawani Amma v. Kunjikutty P.M. Pillai, AIR 2000 SC 2301).