Through the eyes of of a founding feminist.

AS one of the intellectual founders of the women's movement, Susan Brownmiller knows times are tough for feminists. Not only has the Equal Rights Amendment failed repeatedly in recent years, but many women of the new generation openly disown the militancy that characterized feminism's formative years.

At the same time, a recent spate of books written by such movement founders as Betty Friedan and Germaine Greer have been greeted with nothing short of critical catcalls for selling out their original radical ethic. Ms. Brownmiller's own new book, ''Femininity,'' a none-too-charitable look at the Western feminine aesthetic, has earned the charge of being simply outmoded militancy.

As a veteran journalist and the writer of ''Against Our Will,'' a documented study of rape in Western civilization which was considered one of the most forceful feminist works when it appeared in 1975, Ms. Brownmiller is quick to admit that times have indeed changed. In a post-feminist decade that many observers define by a search for fresh gender distinctions, she insists that the times are marked more by political lassitude and moral polarization. In a society grown increasingly competitive - economically, socially, and professionally - she sees many women returning to traditional feminine values.

Despite newly progressive attitudes toward rape victims and two-paycheck households, she maintains that many women face a buttressed standard of femininity - an ultimately self-defeating aesthetic she says is based upon a ''recognition of (female) powerlessness.''

''It could not escape my notice,'' she writes in ''Femininity,'' ''that more women supported the Equal Rights Amendment . . . than could walk out of the house without their eye shadow.'' Women today, she adds, are more fearful of ''being judged impolite'' than of being physically violated. It is the kind of thesis that predictably draws fire; even so, the author confesses she has been surprised by the lack of generosity in her detractors.

During a recent spring afternoon in her light-filled Greenwich Village penthouse, the author talked about her book, critical reaction to it, and the current challenges that women face. In the wide-ranging conversation, this slight woman, dressed simply in trousers, soft shirt, and flat-heeled shoes, touched on a number of topics, including the recent New Bedford rape case, the possibility of a woman vice-president, and the state of feminism today.

''Books that make an impact usually have a movement behind them,'' she says. '' 'Against Our Will' hit at the right time. It reflected an entire new wave of thinking, when there were rape crisis centers in every major city. But all these new (feminist) books are just a publishing accident. There is no new wave of thinking coming up the pike.''

Germaine Greer's controversial new book, ''Sex and Destiny'' - a book Ms. Brownmiller declined to review and has yet to read - she dismisses with, ''I don't understand what she is saying about third-world women being so happy. I don't believe they are.''

As to the possibility of a woman vice-presidential candidate, she is unsure whether this is political window dressing or real commitment. ''I suppose the country has to think about it as a general idea before someone can come along and really make a bid for it successfully,'' she says with a shrug.

Despite this current lack of ideological urgency, Ms. Brownmiller takes comfort in the women's movement for ''lasting as long and creating as many changes as it did.'' Particularly in America, she says. ''It's such a nonideological country and such a pleasant place for most people that militancy seems very foreign to us.'' She points to the recent guilty verdicts in the New Bedford rape trial as symptomatic of some of the changes fostered by the women's movement. Although she adds, ''When ethnic pride is at stake, it's framed in terms of the male image. All the (Portuguese) community's sympathies went with their young men instead of the woman.''

But what seems of greater concern to this writer-cum-feminist are the generations of women who subsequently availed themselves of the fruits of feminism while denigrating much of the early, strident efforts. It's an attitude , she says, that causes many early feminists to feel ''betrayed.''

''That's what troubles me about young women who've had doors opened for them by those of us who are older,'' she says thoughtfully. ''Of course, they haven't had to struggle as hard. But they don't understand that these are very recent gains and they can be taken away. I just remember the '50s and how unfashionable it was (for women) to want a career. I could see it happening again here. One of the reasons it's not is that the economy is such that people seem to need a two-paycheck family.''

Calling herself ''a biological determinist,'' Brownmiller insists that this is one area where women are still struggling. She uses the term ''dual-purpose ambition'' to describe the current sociological plight: women's desire to bear and raise children and the growing drive for professional success.

''Many of us are refusing to define ourselves by our reproductive biology,'' she says. ''I certainly do - I'm a woman who has chosen not to have children. But it is very difficult to reconcile these two (desires), particularly in a very competitive society.'' It is not enough, she believes, for women to decide to have it all. ''I don't think they can have it all,'' she insists. Why? Because men, she says, still set the standards of achievement.

''I don't see why men should have to step aside and wait for women to catch up after they've taken time off to have children,'' she says. ''That's a very difficult truth for a lot of feminists who don't want to believe there are these differences or that they could be a handicap. It's a real hard truth.''

Not surprisingly, some critics have charged that the Brownmiller position is itself sexist. Megan Marshall, author of the new book ''The Cost of Loving: Women and the New Fear of Intimacy,'' wrote in The Nation that Susan Brownmiller espouses an old adage, that ''everything male is inherently freer and therefore more desirable.'' But Ms. Brownmiller is willing to ask, ''Isn't there something positive in femaleness that we want to keep, to propose as a general model for everyone? That's a genuine question. 'Why can't men be more nurturing?' Well they should be. . . . But I feel if you're going to be a writer (for instance), you've got to be disciplined about it, and the distractions considered typically feminine don't help you achieve.''

Indeed, she finds the current revival of femininity - ''a grand collection of compromises,'' as she calls it - discouraging. And she is quick to discredit those who question traditionally male standards of achievement. ''I resent it when some women try to put forward some superior philosophy of womanhood as an excuse for why they're not going to stay in there and do whatever it is they once thought they would do. It's very hard, and it doesn't get easier.''

Women, she says, have often indulged themselves in distracted and ''nonlinear'' thinking patterns. ''This isn't simply a stereotypical or negative portrayal. There is a very good reason for it. When you're listening with one ear for baby's crying in the other room, you can become a distracted person. But beyond that women have often encouraged it in themselves, and men have encouraged it, and I don't like it. Women can think like men, but it means pursuing goals and not getting distracted by irrelevancies.''

She concedes that her own professional success has not come particularly easily. After spending years as a journalist at the Village Voice and ABC-TV, she took five years to research and write ''Against Our Will'' and four years to do ''Femininity.'' Between the books, a time when she says most men would have married and started a family, she felt unable to do so. ''People who make a big push in their 20s and 30s like I did think, 'Whew.' Well it doesn't stop there.'' Ms. Brownmiller points to her own mother as a sort of reverse role model. ''She never got to do any of the things she wanted to do, and I didn't want to make that same mistake.''

While she possesses high hopes for her latest book's impact - ''It would be enough if women would understand that it wasn't an accident that the feminine aesthetic arose and flourished'' - Susan Brownmiller says too that if the women's movement ends completely, she will cease to write about it. ''I believe one should write for an audience and not just to express oneself. I don't care to be a lonely philosopher writing for posterity.''