The following principles concerning coincidences will be found reliable as working laws:

First

As a general proposition, the law of coincidences is that when two phenomena always coincide they are either connected as "cause and effect" or are the " effect of a common cause." But if they do not always coincide, neither of these is proved. They may then be the effects of separate causes working in their respective planes.

The first question is, Do the phenomena always coincide? The importance of a wide generalization is often lost sight of, and erroneous conclusions are asserted with all the confidence of demonstration. A physician who lives near the sea says that during the past five years he has noted the hour and minute of death of ninety-three patients, and that each has "gone out with the tide" save four, who died suddenly by accident. Yet about thirty-two years ago, a writer in the English "Quarterly Review" claimed to have ascertained the hour of death in 2880 instances of all ages. His observations show that the maximum hour of death is from 5 to 6 o'clock a. m., when it is 40 per cent, above the average; the next during the hour before midnight, when it is 25 per cent, in excess. Between 9 and 10 o'clock in the morning it is 17 1/2 per cent, above, but from 10 a. m. to 3 p. m. it is 16 1/2 per cent, below the average. From 3 to 7 in the afternoon the deaths rise to 5 1/2 per cent, above the average, and then fall from that hour to 11 P. M., averaging 6A per cent, below mean. It is probable that both these observations are worthless in view of the small number of instances covered. It is clear that they do not concur; yet, taken separately, each would seem conclusive.

Second

Astronomical predictions are based upon a series of unvarying coincidences, in most cases in harmony with laws whose operations can be tested at any time. If these phenomena were irregular and unclassifiable such predictions would be wholly uncertain; but because they usually coincide, and when they do not, interfering causes can be traced, ellipses can be foretold for thousands of years in advance, and discoveries such as those of Uranus and Neptune be made.

Third

Chemistry and cognate sciences also work with fixed phenomena, so that when the most diverse elements are combined and effects observed, formula) cau be deduced by which at all times the same effects can be produced.

Fourth

Many of the most wonderful inventions have been made by seeming accident; for example, photography. But reflection upon the accident reveals the cause; the cause and the effect are seen to be scientific coincidences, and the art with its principles and practice is the result.

Fifth

The performances of jugglers are in harmony with the established methods of nature. The charm of their exploits is in successful concealment of the causes, rapidity of motion, distraction of attention, and shrewdly contrived illusions of the senses.

Sixth

It is essential to remember that so-called "laws of chance" reflect no light on the order of sequence. It may be rendered probable by those laws that a certain event will not occur on the average more than once in a million of times; but this gives no assistance in determining the order in which any two occurrences will take place. Thus, if it be shown that an event will occur once in a million of times, in the first million it may be the last in the series, and in the second it may be the first; and that will bring them side by side. Many years ago there was a famous lawsuit in New England. A wealthy woman died, leaving large sums for benevolent purposes, and to her niece already very rich almost a million of dollars. The niece made strenuous efforts to break the will. A codicil was produced, the signature of which was found to be exactly like another signature of the testatrix. It was hinted, if not explicitly charged, by the counsel for the will that it was a forgery. Professor Peirce of Harvard University was brought in as a witness. He testified that not more than once in many millions of times would two signatures of the same person be written precisely alike. From this it was designed to raise the presumption that where there is an exact coincidence it must have been done by tracing. The court sustained the will on other grounds, and declined to decide that question. But the force of a presumption of this kind is much weakened, if not destroyed, by the fact that all to which Professor Peirce testified might be true, yet the two similar signatures might occur in the same month. Mr. Proctor states it thus:

The balance is restored just as chance directs. It may be in the next thousand trials, it may not be before many thousands of trials. We are utterly unable to guess when or how it will be brought about.

The business of life insurance can be carried on with certainty, provided the system be constructed upon averages deduced from a sufficiently large number of lives; but the employment of a smaller number would make it ruinous. It is clear that "expectation of life," so called, cannot give the slightest hint as to the probable duration of the life of any man insured under a perfectly reliable system.

Seventh

When a phenomenon is seen with which human beings are not directby connected as actual or possible agents, and which appears to be unlike the course of nature, it should be studied scientifically to ascertain its cause. By such investigations everything now attributed to natural forces has been wrested from the domain of superstition. The work began almost contemporaneously with the beginning of the historic period. Its results are now the inheri-tance of the school-boy. He understands the causes of many things which were formerly attributed, even in classic Greece and Rome, to supernatural interferences.

Eighth

When phenomena are presented by human beings for which no natural cause is assigned and none appears, the first philosophical inquiry is, Is this deception or jugglery? Here the question of moral character comes into view. Has this person a motive to deceive? Is his character such as to raise doubts whether he be honest? The peculiar influence of that phase of human nature which loves to startle, to be regarded as extraordinary, either in action, knowledge, or susceptibility, and the strange opinions and morbid conditions which give fascination to the exercise of the ability to deceive, must not be ignored. When pay is received for such performances, the probability of dishonest}' is strong. The possible paralleling of the phenomena by confessed jugglers is also an important consideration.

Assuming, however, that no ground to suspect jugglery or deceit can be found, the next question is, Do the phenomena go beyond what is known of the possibility of chance coincidences? Not until it is shown that legerdemain cannot produce the effects; that most painstaking investigation can find no explanation and no antecedent in the order of nature; and, further, that the phenomena transcend the possible bounds of coincidences, is there the least presumption that the cause is supernatural. Yet comparatively few of the investigators of occult phenomena have taken pains to comprehend the facts and principles of natural science or the tricks of jugglers, some of whom have been masters of science, or to comprehend the vast possibilities of coincidence.

It should not be supposed that common sense and learning, without special experience, qualify persons to investigate these things. Yet physicians who would sneer with just contempt at a non-professional person who should attempt to give an opinion on a difficult question in medical science, and lawyers who would despise a layman presuming to appear as a judge of abstruse legal questions, and ministers who have given no attention to methods of deception or to the " night side of nature," will join with merchants, teachers, and farmers to pronounce upon subjects much further removed from their spheres than are the pursuits of those whom they call "laymen" from their own; and, because they cannot see how these things can be performed or explained, will give support by testimonials and affirmations of mystery to every new, or renewal of an ancient, superstition. Thus astrology and divination were maintained, and so vast structures of deception at the present day are upheld.