To accept Velikovsky's theory of ancient astronomical events, one must doubt the capacity for remembering details on the part of the ancient peoples who recorded such events as red rivers, manna from heaven, plagues of flies, etc. A more sweeping attack on the memories of ancient peoples is made by Erich von Daniken in his Chariots of the Gods? Unsolved Mysteries of the Past. Von Daniken claims that the myths, arts, social organizations, etc., of ancient cultures were introduced by astronauts from another world. He questions not just the capacity for memory, but the capacity for culture and civilization itself, in ancient peoples. Prehistoric humans did not develop their own arts and technologies, but rather were taught art and science by visitors from outer space.
Most critics of von Daniken's theory point out that prehistoric people were not the helpless, forgetful savages he makes them out to be. (They must have at least been intelligent enough to understand the language and teachings of their celestial instructors--no small feat!) We have no reason to believe our ancient ancestors' memories were so much worse than our own that they could not remember these visitations well enough to preserve an accurate account of them. No evidence would make it plausible that ancient myths and religious stories are the distorted and imperfect recollection of ancient astronauts recorded by ancient priests. The evidence to the contrary--that prehistoric or `primitive' peoples were (and are) quite intelligent and resourceful--is overwhelming. The theory of alien teachers is inconsistent with what we already know from anthropology and archaeology.
Where is the proof for von Daniken's claims? Well, he produced photographs of pottery which he claimed had been found in an archaeological dig. The pottery was said to have been dated from Biblical times. It is interesting because it depicts flying saucers. However, investigators from the fine public television science program Nova found the potter who had made the allegedly ancient pots. They confronted von Daniken with evidence of his fraud. His reply was that his deception was justified because some people would only believe if they saw proof! This annoying trait of deception from noble motives seems quite common among pseudoscientists.
It is possible that visitors from outer space did land on earth a few thousand years ago and communicate with some human beings. But it seems more likely that prehistoric peoples themselves were responsible for their own art, technology and culture. Why concoct such an explanation as von Daniken's? To do so may increase the mystery and romance of one's theory, but it also makes it less reasonable, especially when one's theory seems inconsistent with what we already know about the world.
further reading
De Camp, L. Sprague. The Ancient Engineers (New York: Ballantine Books, 1977).
Randi, James. Flim-Flam! (Buffalo, New York: Prometheus Books,1982), ch. 6.
Sagan, Carl. Broca's Brain (New York: Random House, 1979), ch. 5. "NightWalkers and Mystery Mongers: Sense and Nonsense at the Edge of Science."
Story, Ronald. The Space-gods Revealed: a Close Look at the Theories of Erich von Däniken, 2nd ed. (New York: Barnes & Noble, 1980).