IN A PUFF, our notions of free will and personal responsibility may have to change in the face of a flurry of new liability suits filed against the major cigarette companies.

Twenty years after a first wave of unsuccessful cases were engendered by the Surgeon General's conclusion that smoking is linked to lung cancer and heart disease, new research and new attitudes have emboldened anti-smokers to try again.

And this time, personal-injury lawyer Melvin Belli thinks he has a winning strategy.

In a suit that will go to trial this week in Santa Barbara, Calif., Belli says that he will contend that the R.J. Reynolds Tobacco Company, the defendant, knew that cigarette smoking was addictive long before the Surgeon General's report but failed to inform consumers of the risk. He represents the family of John M. Galbraith, an insurance-company executive who died of lung cancer in 1982 at the age of 69, after 50 years of smoking.

In defense, John L. Strauch, Reynold's lawyer, says that he will argue that the issue is not addiction, but "personal accountability for one's actions."

THE LIVING LEGEND of Edgar Pierce Professor Emeritus of Psychology B.F. Skinner looms large in the philosophy of the plaintiff's case. For they argue, in effect, that the individual is no more than a product of his environment. The cigarette is a strong--albeit pernicious--reinforcer that the tobacco companies have made contingent on the behavior of cigarette-buying. Conveniently, this behavior increases the profits of the tobacco companies. But it also kills people.

The counter-argument of the tobacco companies will no doubt be a reprise of the criticism Skinner has faced from the beginning. But of course we have free will, they'll say; people smoke because they want to.

Yes, people who smoke want to, but Skinner would ask, why do they want to? Since Pasteur, we no longer believe in the spontaneous generation of life, yet we still believe in the spontaneous generation of thoughts and feelings. Thoughts and feelings, though, have a physical basis--the brain. And the brain is changed by our every interaction with the environment. We want to, then, because of some unique personal history of interaction with the environment.

The personal history of most smokers is rich with the availability and advocacy of cigarettes. Billions of dollars have been spent by the tobacco companies over the past 60 years to modify the behavior of consumers. In fact, the popular cigarette slogan, "I'd walk a mile for a Camel," was written by the first American behaviorist, John B. Watson, who had lost his professorship at Johns Hopkins and ended up as an advertising executive at J. Walter Thompson in New York.

So far, it seems that the behaviorist position would lead us to find for the plaintiff. After all, the tobacco companies knew that cigarettes were strong, reinforcers for many people yet still sold them. But not so fast. What about the behavior of the tobacco companies?

TOBACCO COMPANIES are controlled by environmental contingencies just as surely as individual smokers are. Society has made reinforcement for these companies (i.e., profits) contingent on cigarette-selling behavior. Unfortunately, people die as a result. But do the tobacco companies have a "choice"? The behaviorist says no.

And there's the rub. Behaviorism is not compatible with our current conception of personal responsibility, for the latter arises from free will, which the behaviorist denies. There are no bad people, the behaviorist argues, only bad environments. For the behaviorist, society is on trial in every case.

Melvin Belli, then, has chosen the wrong argument. His position, taken to its logical conclusion, arrives at behaviorism. And behaviorism questions the very foundations of our judicial system.

Until we remake our society on a different conception of human nature, people must continue to be free to choose and to be responsible for their choices. If Belli makes addiction the crux of his argument this week, the court would be wise to find against him.

Like Cordelia, Belli had better mend his speech a little, lest he mar his fortunes. He--and the behaviorists--may be right, but as Cordelia learned, sometimes the truth does not conquer.