2. 1950 Contraception and control of disease is revising relations between the sexes to an extent that will change our entire social and economic structure.

1965 This trend is so much more evident now than it was fifteen years ago that I am tempted to call it a fulfilled prophecy. Vast changes in sex relations are evident all around us - with the oldsters calling it "moral decay" and the youngsters ignoring them and taking it for granted. Surface signs: books such as Sex and the Single Girl are smash hits; the formerly taboo four - letter words are now seen both in novels and popular magazines; the neologism "swinger" has come into the language; courts are conceding that nudity and semi - nudity are now parts of the cultural mores. But the end is not yet; this revolution will go much farther and is now barely started.

The most difficult speculation for a science fiction writer to undertake is to imagine correctly the secondary implications of a new factor. Many people correctly anticipated the coming of the horseless carriage; some were bold enough to predict that everyone would use them and the horse would virtually disappear. But I know of no writer, fiction or nonfiction, who saw ahead of time the vast change in the courting and mating habits of Americans which would result primarily from the automobile - a change which the diaphragm and the oral contraceptive merely con - firmed. So far as I know, no one even dreamed of the change in sex habits the automobile would set off.

There is some new gadget in existence today which will prove to be equally revolutionary in some other way equally unexpected. You and I both know of this gadget, by name and by function - but we don't know which one it is nor what its unexpected effect will be. This is why science fiction is not prophecy - and why fictional speculation can be so much fun both to read and to write.

1980 (No, I still don't know what that revolutionary gadget is - unless it is the computer chip.) The sexual revolution: it continues apace - FemLib, GayLib, single women with progeny and never a lifted eyebrow, staid old universities and colleges that permit unmarried couples to room together on campus, group marriages, "open" marriages, miles and miles of "liberated" beaches. Most of this can be covered by one sentence: What used to be concealed is now done openly. But sexual attitudes are in flux; the new ones not yet cultural mores.

But I think I see a trend, one that might jell by 2000 A.D. The racial biological function of "family" is the protection of children and pregnant women. To accomplish that, family organization must be rewarding to men as well .. . and I do not mean copulation. There is a cynical old adage covering that: "Why keep a cow when milk is so cheap?" A marriage must offer its members emotional, spiritual, and physical comforts superior to those to be found in living alone if that prime function is to be accomplished.

(Stipulated: there are individuals, both sexes, who prefer to live alone. This is racially self - correcting.)

The American core family (father, mother, two or three children) has ceased to be emotionally satisfying - if it ever was. It is a creation of our times: mobility, birth control, easy divorce. Early in this century the core family was mother, father, four to eight children.. . and was itself a unit in an extended family of grandparents, aunts, uncles, and cousins living near enough (if not in the same house) to be mutually supportive. If a child was ill, Aunt Cora came over to help while Aunt Abby took the other kids into her home. See Mauve Decade fiction.

With increased mobility and fewer children this undefined extended - family pattern disappeared almost without its disappearance being noticed. To the extent to which it was noticed there was often glee at being free of the nuisance of in - laws and kinfolk. It took considerably longer to realize that the advantages had also disappeared.

We will not get a return of the extended family of the sort that characterized the 19th century and the early 20th ... but the current flux of swingers' clubs, group marriages, spouse swapping, etc., is, in my opinion, fumbling and almost unconscious attempts to regain the pleasure, emotional comfort, and mutual security once found in the extended family of two or more generations back.

Prediction: by 2000 A.D. or soon thereafter extended families of several sorts will be more common than core families. The common characteristic of the various types will be increased security for children under legally enforceable contracts.

3. 1950 The most important military fact of this century is that there is no way to repel an attack from outer space.

1965 I flatly stand by this one. True, we are now working on Nike - Zeus and Nike - X and related systems and plan to spend billions on such systems - and we know that others are doing the same thing. True, it is possible to hit an object in orbit or trajectory. Nevertheless this prediction is as safe as predicting tomorrow's sunrise. Anti - aircraft fire never stopped air attacks; it simply made them expensive. The disadvantage in being at the bottom of a deep "gravity well" is very great; gravity gauge will be as crucial in the coming years as wind gauge was in the days when sailing ships controlled empires. The nation that controls the Moon will control the Earth - but no one seems willing these days to speak that nasty fact out loud.

1980 I have just heard a convincing report that the USSR has developed lasers far better than ours that can blind our eyes - in - the - sky satellites and, presumably, destroy our ICBMs in flight. Stipulate that this rumor is true: It does not change my 1950 assertion one iota. Missiles tossed from the Moon to the Earth need not be H - bombs or any sort of bomb - or even missile - shaped. All they need be is massive.. . because they arrive at approximately seven miles per second. A laser capable of blinding a satellite and of disabling an ICBM to the point where it can't explode would need to be orders of magnitude more powerful in order to volatilize a house - size chunk of Luna. For further details see my THE MOON IS A HARSH MISTRESS.

4. 1950 It is utterly impossible that the United States will start a "preventive war." We will fight when attacked, either directly or in a territory we have guaranteed to defend.

1965 Since 1950 we have done so in several theaters and are doing so in Viet Nam as this is written. "Preventive" or "pre - emptive" war seems as unlikely as ever, no matter who is in the White House. Here is a new prediction: World War III (as a major, all - out war) will not take place at least until 1980 and could easily hold off until 2000. This is a very happy prediction compared with the situation in 1950, as those years of grace may turn up basic factors which (I hope!) may postpone disaster still longer. We were much closer to ultimate disaster around 1955 than we are today - much closer indeed than we were at the time of the Cuban Confrontation in 1962. But the public never knew it. All in all, things look pretty good for survival, for the time being - and that is as good a break as our ancestors ever had. It was far more dangerous to live in London in 1664 - 5 than it is to live in a city threatened by H - bombs today.

1980 lam forced to revise the 1950 prediction to this extent: It is no longer certain that we will fight to repel attack on territory we have guaranteed to defend; our behavior both with respect to Viet Nam and to Taiwan is a clear warning to our NATO allies. The question is not whether we should ever have been in Viet Nam or whether we should ever have allied ourselves to the Nationalist Chinese. I do not know of any professional military man who favored ever getting into combat on the continent of Asia; such war for us is a logistic and strategic disaster.

But to break a commitment to an ally once it has been made is to destroy our credibility.