FOR MOST PEOPLE, Oct. 31 is a time to enjoy being pleasantly frightened - as long as their imagination remains in control. But Halloween has not always been a delightful scream.

In fact, Halloween symbols go back to a time when people, young and old, lived in real dread of witches, cats, bats, owls and toads, and ghosts - especially on Halloween.The star of Halloween is the witch. With her black cloak and peaked hat, her broomstick and her cat, the witch is the central symbol of the holiday and the one with the strangest history. The name comes from the Saxon word wica, which means wise one. Witches were believed to foretell the future. Capitalizing on superstitions, witches used magic words and charms to keep away bad luck.

Artists of the Middle Ages often showed witches preparing to fly off to one of their sabbaths. They were usually rubbing themselves with something or being rubbed by someone else. This was the flying ointment.

Angels and devils were supposed to be able to fly, so it was easy to believe that witches, too, could fly. Many witches believed it themselves. Those who were well-off rode on horseback, not on brooms. Poor witches went on foot. With them they carried a broom or pole for vaulting over brooks, streams or thorny patches. No wonder that the Halloween witch is often pictured riding or holding a broomstick.

Witches of old, setting out for a sabbath, often had long distances to go. They were said to be seen on country roads, alone or in groups, laden down with bundles of food and large cooking cauldrons.

At the meeting place, the witches gathered firewood, fresh herbs and ripe berries, and looked for water. Then, with three stout green branches they fashioned a tripod to hold the cauldron, and proceeded to cook their meal.

Most women of the time brewed cauldrons of herbs to cure headaches and backaches, fevers and colds. But a lonely old woman, who was not a witch, might be overheard talking to herself as she stirred her brew. Before long, she might find herself accused of causing measles in a neighbor's child or of blinding a neighbor's horse.

After dark on Halloween, flitting from house to house, there are always at least a few figures draped in sheets, white and ghostly against the night.

There was nothing make-believe about the fears of the Scotch, Irish and English on this same evening years ago. This was the night when ghosts, the spirits of disembodied souls of the dead, were thought to return to their former homes, looking for warmth and cheer. To displease the ghosts was dangerous, for they could punish you.

At Halloween, owls and cats were said to travel with witches. Screech owls nested in hollow trees, seldom giving a sign of their presence until nightfall. Their weird, trembling call and hollow whistle frightened travelers on lonely roads. It sounded so witch-like, the owl could actually be a witch hiding among the trees, for witches, everyone agreed, often took other shapes.

Bats were frightening in themselves. Their heads were weirdly shaped and they had long, menacing, pointed teeth. With an enormous wingspread, they seemed to be able to fly with the aid of some mysterious, evil power. How else could they find their way on the darkest night?

Today it is considered unusual but harmless to tame a toad. But like the bat, the toad is still rather unpopular. At the time of the witch scare, most people in Europe lived on farms or in small villages. Toads appeared everywhere.

Toads were considered poisonous. When a dog chased a toad, people noticed that a dog might come away with a sore mouth or sore eyes. If they handled a toad themselves, their own eyes or nose might burn or itch. No wonder, people said, that witches made familiars of toads. Appearing with witches in so many stories, the toad has become a small but continuing part of Halloween.

Black cats were thought to be the witches' mascots, or sometimes even witches in disguise. Why black? Because after dark, when everything is dim and shadowy, all cats look black.

Halloween, with more ancient beginnings than any other holiday, no longer holds any serious meaning. Children have kept it alive because they love it.