The detective story, and now we include the whole range of mystery or riddle stories, is founded on a fundamental human trait, inquisitiveness. Man is an incarnate interrogation point. The infant's eyes ask questions before his tongue can do so, and soon the inquiring eyes are supplemented by a little outstretched hand, trying to satisfy a curiosity by the sense of touch. But, once having achieved a vocabulary, however small, he uses it almost entirely to make inquiries, until so prominent becomes this trait, that his conversation is cut off altogether, and he is condemned to be visible but not audible.
Attaining further intelligence, his inquiries become more definite and thoughtful, though no less numerous and eager. He seeks books, whether in or out of running brooks; he inquires of authorities, or he reasons out answers for himself, as he grows in body and brain. He meets a friend in the street, he pours out questions. In his business he progresses by one question after another. Is he an inventor? He questions of Nature till he probes her various secrets. Is he a philosopher? He questions his soul.
To quote Mr. Dudeney again:
> "The curious propensity for propounding puzzles is not peculiar to any race or to any period of history. It is simply innate in every intelligent man, woman, and child who has ever lived, though it is always showing itself in different forms; whether the individual be a Sphinx of Egypt, a Samson of Hebrew lore, an Indian fakir, a Chinese philosopher, a mahatma of Tibet, or a European mathematician makes little difference.
> "Theologian, scientist, and artisan are perpetually engaged in attempting to solve puzzles, while every game, sport, and pastime is built up of problems of greater or less difficulty. The spontaneous question asked by the child of his parent, by one cyclist of another while taking a brief rest on a stile, by a cricketer during the luncheon hour, or by a yachtsman lazily scanning the horizon, is frequently a problem of considerable difficulty. In short, we are all propounding puzzles to one another every day of our lives—without always knowing it."
An orator makes his best effects by questions. The Book of Job is impressive largely because it is written in interrogative form.
Many trite quotations are questions. "What is truth?" or "Is life worth living?" arrest our attention because they are debatable queries. Who is not more interested in the Questions of the Day than in the known facts?
According to Mr. George Manville Fenn, the man who invented a wondrous and mysterious plot for a story deserves a palm.
> "He must have been a deep thinker, one well versed in the philosophy of goose quill, knowing that his story would thrill the reader, and that he had achieved the great point of seizing upon that reader's imagination, and holding it, so that he would follow the mystery of the fiction to the very end. It may have been the result of some haphazard lucky thought, but still he must have been a careful student of every-day life, and must have duly noted how largely curiosity or the desire to fathom the unknown is developed in the human brain."
As with other human traits, inquiry is inherent to a greater extent and also more largely developed in some minds than in others. Some people say "How do you do?" and wait interestedly for your answer. Others say "How are you?" and without pausing for reply, go on to remark about the weather. But it is the people who are interested in answers who care for detective stories. It is the people who care for the solution of a problem who write and read mystery tales.
One who has studied these questions from many points of view, and, above all, noted how a story will "catch on," and almost electrically seize the imagination of the reading world, will constantly see that in the majority of cases the most popular fiction of the day is that in which mystery plays a prominent part—a mystery which is well concealed. This is no secret. It is the natural desire for the weird and wonderful—that hunger for the knowledge of the unknown which began with the forbidden apple; and the practiser of the art in question merely grows for those who hunger, a fruit that is goodly to the eye, agreeable to the taste, and one that should, if he—or she—be worthy of the honored name of author, contain in its seeds only a sufficiency of hydrocyanic poison to make it piquant in savor. It is no forbidden fruit that he should offer, merely an apple that is hard to pick—a fruit whose first bite excites fresh desire, whose taste brings forth an intense longing for more, and of which the choicest and most enticing morsel is cleverly held back to the very end.
As Mr. Dudeney observes:
> "It is extraordinary what fascination a good puzzle has for a great many people. We know the thing to be of trivial importance, yet we are impelled to master it, and when we have succeeded there is a pleasure and a sense of satisfaction that are a quite sufficient reward for our trouble, even when there is no prize to be won. What is this mysterious charm that many find irresistible? Why do we like to be puzzled? The curious thing is that directly the enigma is solved the interest generally vanishes. We have done it, and that is enough. But why did we ever attempt to do it? The answer is simply that it gave us pleasure to seek the solution—that the pleasure was all in the seeking and finding for their own sakes. A good puzzle, like virtue, is its own reward. Man loves to be confronted by a mystery—and he is not entirely happy until he has solved it. We never like to feel our mental inferiority to those around us. The spirit of rivalry is innate in man; it stimulates the smallest child, in play or education, to keep level with his fellows, and in later life it turns men into great discoverers, inventors, orators, heroes, artists and (if they have more material aims) perhaps millionaires."
But the kernel of their interest is resolution.
A mystery and its solution designedly set forth in narration, implies a previous sequence unknown to the reader.
It is this re-solution that attracts the alert brain, and stimulates the reader to solve for himself a problem whose answer he will shortly learn. But he wants to learn that answer as corroborative proof of his own solution, and not as a revelation.
It is this instinct, great in some, small or perhaps even entirely lacking in others, that makes a mind interested in puzzles or mysteries.