Atmosphere: 1960s relics; wear old jeans.

Hours: 11:30 a.m. to 3 p.m. and 6 p.m. to midnight Monday; 11:30 a.m. to midnight Tuesday, Wednesday and Thursday; 11:30 a.m. to 1 a.m. Friday; 5 p.m. to 1 a.m. Saturday; and 5 p.m. to midnight Sunday.

Price range: 75-cent snacks to $5.30 dinner specials.

Reservations: For groups of eight or more.

Credit cards: None.

Special facilities: Accessible to patrons in wheelchairs; highchairs and booster chairs; on-street parking.

The receding tides of the 1960s left behind a few backwaters that still nourish the relics of Washington's counterestablishment. Food For Thought, a kind of countercultural analogue to a Williamsburg tearoom, also functions as a neighborhood social center. Think of it as a large village diner, catering to a Dupont Circle community of artists and activists.

It's an interesting and undemanding place to take the family, whether yours is nuclear, extended or simply fragmented. Your budget should take priority over esthetics, however, or you may be put off by the sight of the cook behind the counter, his abundant hair only tenuously bound in a ponytail, and his muscular arms emerging from a T-shirt bearing the slogan, "Split Heads, Not Atoms."

At the rear of the barnlike dining room, beyond the aging black plastic booths and vinyl-covered tables, is a small stage where each evening a singing guitarist or pianist entertains.

The restaurant's food reflects the homely virtues and faults of the time when everyone was discovering natural foods. The menu seems scarcely changed since Food For Thought opened nine years ago.

On the good side are its salads and sandwiches, made of fresh and wholesome ingredients. They are simple, generous and low-priced. Potato chips are natural, and the salad dressings are homemade. The roasted turkey breast is the honest article in a substantial sandwich that combines it with provolone cheese, mushrooms, lettuce, tomato and blue cheese dressing on whole-wheat berry bread ($3.55).

A recent dinner at Food For Thought, however, confirmed the impression we've had over the years that anything requiring real cooking is a bit of a gamble. We tried a couple of the day's specials and were sorry we had strayed from salads.

A cup of gazpacho ($1.25) was underseasoned and oddly thick, tasting as if it had been made from tomato sauce or puree instead of fresh tomatoes. Mushrooms Berkeley ($3.85), a treacle-sweet stew of overcooked green peppers and mushrooms served over brown rice, reminded us of unsuccessful experiments from our communal past.

Then there was the turbot in shrimp-cheese sauce ($5.25) that drew all the pejorative comments a fish could: oily, bland, bitter, fishy. No sign or taste of shrimp was detectable, although there was a mysterious little mound of grated cheese on top. Luckily, an excellent dinner salad accompanied it.

The children, both 3-year-old culinary conservatives, ordered the nitrate-free, all-beef hot dogs ($1.55). Served on whole-wheat rolls, they had an agreeable salty smokiness and were far superior to the supermarket variety.

We also ordered a fruit and nut salad ($2.45) for the two to share. This is one of Food For Thought's best bargains: a generous bowl of apples, bananas, raw cashews, raisins and sunflower seeds bound together with a light honey-yogurt dressing. It's good and ample enough to make a light dinner for an adult.

For dessert, we passed up the homemade carrot cake that we knew from previous visits to be delicious and ordered the fudge almond supreme ($1.70), a small square of pudding-like chocolate, strongly flavored with almond extract. We found one small piece, topped with whipped cream, plenty for two.

With drinks--two unfiltered apple juices for the children, a draft beer, gin and tonic and a cup of coffee--tax, tip and a couple of dollars for the musician, our bill was $34.35, a little high by Food For Thought standards. Next time, we'll cast a warier eye on those improvisational specials and keep the bill to less than $20 for three people.