In the daily review of ''The French Lieutenant's Woman'' I characterized the framing story as ''curiously flat,'' which was less a judgment than a description. I suspect that the ephemeral nature of the contemporary love story, beautifully defined in a series of brief scenes, was exactly the point Mr. Pinter wanted to make in contrast to the feelings of desperation and loss experienced by the Victorian lovers. However, because movie making as a metaphor for today's casual, yet speeded up attitudes toward love, sex and even politics, has been much more movingly and pointedly explored, especially in Francois Truffaut's superb ''Day for Night,'' one must be a little surprised that Mr. Pinter would dare follow the same route. For all of Mr. Pinter's daring, he's not really dared anything new. Mr. Fowles's foreword to Mr. Pinter's screenplay does, however, offer a number of provocative statements about the business of turning novels into films - and it is, of course, a business as much as anything else.
Some samples follow.