Germain Ravera, a construction worker here, is currently going through his fifth trial on the same charge. He refuses to return his 10-year-old son to his former wife, who was awarded custody of the boy after their divorce.

A banal affair, to be sure, but one among many similar cases that underline the extent to which France, in contrast to other modern nations, has been unable to adapt easily to social changes.

Divorce has been traditionally rare in France, partly because of the influence of the Catholic Church, partly because the family was considered sacred, and partly becuase the rights of women to reject their husbands were limited. In recent years, however, old practives have disappeared.

The law, responsive to new attitiudes, has become more flexible. And divorce, while not as frequent as in the United States, is no longer a taboo. Last year, for example, one out of five French couples divorced. Here in Paris, where the atmosphere is more liberal, a quarter of the marriages ended legally.

But despite this shift, the courts still regard divorced fathers as unfit to raise their children. As a result, wives are awarded custody of kids in 85 percent of divorces. Moreover, more children are sent to institutions or put in the care of grandparents than are given to their fathers.

A growing number of men are beginning to argue that the claim of women for equality ought to carry with it the possiblity for divorced fathers to keep their children. They point out, among other things, that the large proportion of women who work are no better qualified to care for kids than their former husbands.

In typical French fashion, these men have formed an association, the Pateranl Condition, to lobby on their behalf. They have so far registered little progress, however.

The police are reluctant to get involved, since they find that fathers deprived of their children often react violently when threatened. Besides, cops here hate to intrude into family squabbles.

Judges, on the other hand, tend to be tough. Last year, for instance they sent 400 divorced fathers to jail for violating custody decisions.The Ministry of Justice estimates, in addition, that several hundred men fled the country with their kids last year rather than obey court rulings.

One judge here defends his usual inclination to give the custody of children to their mothers on the grounds that he is only conforming to he social consensus. As he puts it:

"Society believes that a mother whose child is taken away from her is a bad woman, and her reputation is therefore damaged. A fater deprived of his kid doesn't suffer the same opprobrium."

On the contrary, men who fight to keep their children face serious battles, even when the kids themselves plainly express a desire to stay with their fathers. Such has been the experience of Germain Ravera, the construction worker whose trials have been dragging on for months.

Ordered to live with his mother, Ravera's son Pascal fled home and hitchiked 150 miles to rejoin his father. The mother formally charged her ex-husband with kidnapping the boy, and the police arrested Ravera.

During an initial hearing last year, psychiatrists testified that the child ran the rish of mental trouble if he remained with his mother. One even suggested that the boy might commit suicide. But the judge returned the kid to his mother, calling on Ravera to "cease the pursuit of his illusions."

But Ravera defied the verdict, and he is now on trial again.He could be sentenced to as much as a year in prison if convicted.

The publicity given Ravera's struggle has laterly focused the spotlight on even more dramatic cases, like that of Roger Poulin, who killed himself a couple of months ago because he feared that his 3-year-old son would be taken from him.

Most disputes between estranged husbands and wives over children are less sensational, though, revolving as they do around such issues as the right to visit children. In general, the courts favor women.

All this indicates, then, that child custody decisions have not yet caught up with the divorce laws, largely because motherhood and marriage are viewed differently.

This emerged not long ago in the trial of a man who murdered his ex-wife for refusing to allow him to see their son. Summing up the problem, the prosecutor said: "Until fatheres can breast-feed them, children will be given to their mothers -- whether we like it or not."