A three-judge bench of Supreme Court delivered this landmark judgment [around topics like Definition of Mental Cruelty; Burden of Proof; Proof beyond reasonable doubt not necessary; Condonation of Cruelty], where in it was held that,

HEAD NOTE in the judgment says,

(i) Normally this Court would not have gone into evidence especially as the High Court itself could not have gone into the evidence in second appeal. Section 100 of the C.P.C. restricts the jurisdiction of the High Court in second appeal to questions of law or to substantial errors or defects in the procedure which might possibly have produced error or defect in the decision of the case upon merits. The High Court came to the conclusion-that both the courts below had failed to apply the correct principles of law in determining the issue of cruelty. Accordingly the High Court proceeded to consider evidence for itself. Under s. 103 C.P.C. the High Court can determine any issue of fact if the evidence on the record is sufficient but if the High Court takes upon itself the duty of determining an issue of fact, its powers to appreciate evidence would be subject to the same restraining conditions to which the power of any court of facts is ordinarily subject. The limits of that power are not wider for the reason that the evidence is being appreciated by the High Court and not by the District Court. While appreciating evidence, inferences may and have to be drawn but courts of facts have to remind themselves of the line that divides an inference from guess work. Normally this Court would have remanded the matter to the High Court for a fresh consideration of the evidence but since the proceedings were pending for 13 years the Court itself went into the evidence.
(ii) The burden of proof in a matrimonial petition-must lie on the petitioner because ordinarily the burden lies on the party which affirms a fact, not on the party which denied it. This principle accords with commonsense, as it is much easier to prove a positive than a negative. The petitioner must, therefore. prove that the respondents had treated him with cruelty within; the meaning of r. 10(1)(b) of the Act. But the High Court was wrong in holding that the petitioner must prove his case beyond a reasonable doubt. The normal rule which governs civil proceedings is that a fact is said to be established if it is proved by preponderance of probabilities. Under s. 3 of the Evidence Act a act is said to be. proved when the court either believes it to exist or if considers its existence so probable that a prudent man ought, in the circumstances, to act upon the supposition that it exists. The first step in this process to fix the probabilities. the second to weigh them. The impossible is weeded out in the first stage, the improbable in the second. Within the wide range, of probabilities the Court has often a difficult choice to make but it is this choice which ultimately determines where the preponderance of probabilities lies. Important issues like the status of parties demand closer scrutiny than those like the loan on a promissory note. Proof beyond reasonable doubt is proof by a higher standard which generally governs criminal trials or trials involving enquiries into issues of quasi-criminal nature. It is wrong to import such considerations in trials of a purely civil nature. Neither s.10 nor s. 23 of the Hindu Marriage Act requires that the petitioner must prove his case beyond reasonable doubt S. 23 confers on the court the power to pass a decree if it is satisfied on the matters mentioned in Clauses (a) to (e) of that Section. Considering that proceedings under the Act are essentially of a civil nature the word ’satisfied’ must mean satisfied on a preponderance of probabilities and not satisfied beyond a reasonable doubt. The society has a stake in the institution of marriage and, therefore, the erring spouse is treated not as a mere defaulter but as an offender. But this social philosophy, though it may have a bearing on the need to have the clearest proof of an allegation before it is accepted as a ground for- the dissolution of marriage, it has no bearing on the standard of proof in matrimonial cases. In England, a view was at one time taken that a petitioner in a matrimonial petition must establish his or her case beyond a reasonable doubt but the House of Lords in Blyth v. Blyth has held that the grounds of divorce or the bars to the divorce May be proved by a preponderance of probability. The High Court of Australia has also taken a similar view.
(iii) On the question of condonation of cruelty, a specific provision of a specific enactment has to be interpreted, namely s. 10(1) (b). The enquiry, therefore, has to be whether the conduct charged as cruelty is of such a character as to cause in the mind of the petitioner a reasonable apprehension that it will be harmful or injurious for him to live with the respondent. It is not necessary, as under the English Law, that the cruelty must be of such a character as to cause danger to life, limb or health or as to give rise to a reasonable apprehension of such a danger. It is risky to rely on English decisions in this field although awareness of foreign decisions can be a useful guide in interpreting our laws. The apprehension of the petitioner that it will be harmful or injurious to live with the other party has to be reasonable. It is, however, wrong to import the concept of a reasonable man as known to the law of negligence for judging matrimonial relations. The question is not whether the conduct would be cruel to a reasonable person or a person of average or normal sensibilities but whether it would have that effect on the aggrieved spouse. That which may be cruel to one person may be laughed off by another and what may not be cruel to an individual under one set of circumstances may be extreme cruelty under another set of circumstances. The Court has to deal not with an ideal husband and an ideal wife but with the particular man and woman before it. The only rider is that of s. 23(1)(a) of the Act that the relief prayed for can be decreed only if the petitioner is not taking advantage of his own wrong.
(iv) Acts like the tearing of the Mangal Sutra, locking out the husband when he is due to arrive from the office, rubbing of chilly powder on the tongue of an infant child, beating a child mercilessly while in high fever and switching on the light at night and sitting by the bedside of the husband merely to nag him are acts which tend to destroy the legitimate ends and objects of matrimony. The conduct of wife amounts to cruelty within the meaning of s. 10(1) (b) of the Act. The threat that she would put an end to her own life or that she will set the house on fire, the threat that she will make the husband lose his job and have the matter published in newspapers and the persistent abuses and insults hurled at the husband and his parents are all of so grave an order as to ’imperil the appellant’s sense of personal safety, mental happiness, job satisfaction and reputation.
(v) In any proceeding under the Act, whether defended or not, the relief prayed for can be decreed only if the petitioner has not condoned the cruelty. The wife did not take up the plea of condonation in her written statement. The Trial Court did not frame any issue of condonation. The District Court did not address itself on the question of condonation since it did not find the conduct of the wife to be cruel. The High Court held that the conduct of the wife was not cruel and in any case it was condoned. S. 23 (1) (b) casts obligation on the court to consider the question of condonation. Condonation means forgiveness of the matrimonial offence and restoration of spouses to the same position as he or she occupied before the matrimonial offence was committed. Cruelty generally does not consist of a single isolated act. It consists in most cases of a series of acts spread over a period of time. Law does not require that at the first appearance of a cruel act, the other spouse must leave the matrimonial home lest the continued coharbitation be construed as condonation. Such a construction will hinder reconciliation and thereby frustrate the benign purpose of marriage laws. The evidence on condonation consists in this case in the fact that spouse led a normal sexual life despite the various acts of cruelty. This is not a case where the spouse after separation indulge in stray acts of sexual intercourse in which case the necessary intent to forgive and restore may be said to be lacking. Such stray acts may bear more than one explanation but if during cohabitation the spouses uninfluenced by the conduct of the offending spouse, lead a life of intimacy which characterised normal matrimonial relationship, the intent to forgive and restore the offending spouse to the original status way reasonably be inferred. There is then no scope for imagining that the conception of the child could be the result of a single act of sexual intercourse and that such an act could be a stark animal act unaccompanied by the nobler graces of marital life. Sex plays an important role in married life and cannot be separated from other factors which lend to matrimony a sense of fruition and fulfilment. Therefore, evidence showing that the spouse led a normal sexual life even after serious acts of cruelty by one spouse is proof that the other spouse condoned that cruelty. Intercourse in circumstances as obtained here would raise a strong inference of condonation. That inference stands uncontradicted. the husband not having explained the circumstances In which hecame to lead and live a normal sexual life, 
(vi) But condonation of a matrimonial offence is not to be likened to a Presidential pardon which once granted wipes out the guilt beyond the possibility of revival. Condonation is always subject to the implied condition that the offending spouse will not commit a further matrimonial offence either of the same variety as the one condoned or of any other variety. No matrimonial offence is erased by condonation. It is obscured but not obliterated. Condoned cruelty can, therefore, be revived. For revival of condonation it is not necessary that the conduct should be enough by itself to found a degree for judicial separation. The wife in not allowing the husband access to the children cannot be said to have revived the earlier cruelty since the children were of tender age and the only person who could escort them had left or had to leave the matrimonial home for good. The subsequent conduct of the wife has to be assessed in the context in which the husband behaved. The husband persistently accused the wife of insanity and refused to maintain her. In that context, the allegations made by the wife in her letter to the Government cannot revive the original cause of action, though it is true that more serious the original offence the less grave need be the subsequent act to constitute revival.

Citations: [1975 SCC 2 326], [1975 AIR SC 1534], [1976 LW 89 110], [1975 SCR 3 967]

Indiankanoon.org or Casemine link: https://indiankanoon.org/doc/62494/ or https://www.casemine.com/judgement/in/5609abb0e4b014971140d07f

The Bombay High Court dismissal judgment that the Supreme Court also dismissed is here.

The Index is here.