For much of human history, fathering was an afterthought. Motherhood was something we observed. Fatherhood was something we discovered.

Even in this century we established a day for mothers in 1907, a full three years before we gave equal time to the other parents. Now, after 71 years, Father's Day still gets second place on the calendar.

In termns of our culture, as Margaret Mead once put it, "Human fatherhood is a social invention."

So Father's Day is not a bad time to take a look at just what we are inventing, or re-inventing, or trying to re-invent. At no time in our collective memory have the social messages about this parent been quite so confused, quite so contradictory.

Consider, for a minute, a couple of Father's Day Stories, circa 1981. The first stars James Noyes, the man who signed an agreement with a surrogate mother, Nisa Bhimani. His paternity consisted of a vial of sperm. But when the biological mother decided to keep the baby, the biological father was left with no more than his name on a birth certificate.

The second story is about human leukocyte antigen. It was announced this month that H.L.A. blood-typing can be used to prove paternity with a 90-percent degree of accuracy.

The moral of these two tales is an odd one. If you want a baby badly enough to employ a surrogate mother, you may end up with a broken promise. If you don't want a baby, you may end up with a paternity suit.

These stories may be unusal ones, but the attitudes behind them are not. The law treats fathers in strange and similar ways.

Imagine, for example, a fellow named John Jones. Imagine John Jones meets Mary Smith. They have intercourse and Mary gets pregnant. John, whether or not he marries Mary, has no legal say over whether she has an abortion or a baby.

Let's say John and Mary do not marry, but Mary does have the baby. She may then, with absolute impunisty, and a blood test, sue John for child support, even if he wanted her to have an abortion.

There are, of course, other wrinkles in our legal system. If Mary does not sue for paternity and John does not claim his fatherhood, Mary can put up the baby for adoption without his permission.

All this may sound like a testimonial for either male contraceptives or marriage. But we are not quite through. If John and Mary marry and then divorce, in most states he has a less than equal chance of joint custody. Even if John doesn't want the divorce, he may end up being legally pursued for child-support payments.

Most of these laws have been based on some legitimate concerns. Not many of us want to return to the days when fathers had virtual omnipotence over children and wives. Not many of us would like a man to have the right to force a woman into an abortion. Not many of us believe every biological father -- including rapists and artificial inseminators -- should have an equal right to custody.

In some cases there is no way to validate a father's claims without invalidating a mother's. (I have never met a loser in a divorce custody fight who thought the decision was "fair.") In other cases, the law is based on a reality. The reality is that more fathers desert their children than sue for them.

But I am talking about the cumulative effect of the laws governing fathers.

Taken together, the message is that society is far more interested in enforcing a father's responsibilities than his rights. We are more anxious to protect kids from the worst possible fathers than to encourage the best.

This is what we trumpet publicly as we try privately to secure a deeper investment by fathers in their children. The law discourages emotional risk as we try to encourage it. The law may even prompt men to fulfill its negative expectations.

I know there is a complicated relationship between our attitudes and our laws. It's hard to know which should, which does change first: the attitude of fathers or the courts.

But it may be impossible to "invent" a father who is an equal parent in our children's daily lives, if we go on treating them in public life as if they were an afterthought.