Writing popular fiction

is to have him originate on a world essentially like our own Earth, but to have him be a member of another species—besides the ape, from which man most likely descended—such as a lizard-man (my own
Beastchild
creates a sympathetic alien of reptillian nature), a winged man, a creature of the seas, a nocturnal, four-legged predator, or any of countless other possibilities. Robert Silverberg's excellent
Downward to the Earth
postulates intelligent, elephant-like creatures on an Earth-type world. A. E. van Vogt's
Voyage of the Space Beagle
contains a catlike alien that can pass, unchanged, through walls or any other barriers, and my own
Dark of the Woods
is set on an Earth-like world where the native race is a diminutive and delicate human-variant with gossamer and functional wings.
    This second method—creating an alien who comes from an Earth-type world and breathes Earth-mixture atmosphere—helps you avoid a great deal of research, while providing a suitably eerie extra-terrestrial being. You don't have to probe in science books if he comes from an Earth-type world—you already know much about him. You can concentrate, now, on extrapolating his physical looks and his culture.
    At this point, considering your plot and your ability, you must decide whether the alien will be handled as a serious character or as a figure for satire and buffoonery. Unless your writing talents are well developed, and unless you are
very
familiar with science fiction, you should avoid the latter approach. You may
think it a simple matter to create a comic alien with too many legs, several eyes, and a squeaky voice, imbue him with a crackpot sense of humor (we all think of ourselves as the master of the funny line, even if we write tear jerkers for a living), and push him on stage. This way lies disaster. Only one writer in recent years has proven continually adept at creating funny aliens and using them to advantage: Keith Laumer's many books, including his Retief novels about an Earth diplomat mixed up in galactic intrigues, usually escape crossing that line between humor and boredom.
    If you intend to develop your alien as a serious character—in either the role of a menacing antagonist or as a compatriot of the hero—you should delve as deeply into the alien's psyche and personality as you would into a human's. Extra-terrestrials do not invade the Earth without purpose—indeed, they should have doubts, aspirations, second thoughts, loves, hates, and prejudices—unless they are megalomaniacs. Also remember that an alien creature, while having motivations just as humans do, will have substantially
different
motivations. Suppose, for instance, that the alien comes from a society where the institution of the family is unheard of, where breeding is a more natural process and less of a personal one than it is with human beings. The effects upon various motivations will be profound.
    Examples of alien characterization, as well as other requirements peculiar to science fiction, will be given later in this chapter.

TIME TRAVEL STORY
    The third plot type in science fiction is the
time travel story
. Ever since H. G. Wells created the form with
The Time Machine
, readers have evidenced a continuing interest in the subject. One reason for this popularity is that the science of time-space is so esoteric, so intangible, that a writer can formulate a "wonderful new discovery" to justify the existence of the time machine and place his story at any point in history: today, tomorrow, next week, a hundred years from now, or a hundred years ago, making for varied and vivid backgrounds and plots. Too, because time travel stories deal with a quantity which people are familiar with—minutes, hours, memories—it seems more real than a story based on science beyond their understanding.
    A time machine can operate in several ways. If the story purpose is best suited by a machine that will only carry passengers into the past (Harry Harrison's
The Technicolor Time Machine)
, the writer need only say so. If he wants a machine that only travels into the future (Wilson Tucker's
The Year of the Quiet Sun)
and then back to the starting point, or if he wants a machine capable of forward and backward time travel, he need only inform the reader, briefly, of the machine's limitations or abilities.
    Trips into the future require the same extrapolated background we have discussed. Trips into the past require a background for the proper period; this can easily be