Morning journal and courier., 1880-06-30
Retrospective Prophecy.

l. VI
 ! story, in the ordinary acceptation of the word, is based upon the interpretation of documentary evidence; and documents would have no evidential value unless historians were justified in their assumption that they have come into existence by the operation of causes similar to those of which documents are, in our present experience, the effects If a written history can be produced otherwise than by human agency, or if the man who wrote given document was actuated by oth- CT than ordinary human motives such docu- ments are of no more evidential value than so many arabesques. Archaeology, which takes up the thread of history beyond the point at which documentary evidence fails us, could have no existence, except for our well-ground- ed confidence that monuments and works of art, or artifce, have never been produced by causes different in kind from those to which they now owe their origin. And geology. which traces back the cause of history beyond the limits of archaeology, could tell us noth-
 ing except for the assumption that, millions of years ago, water heat, gravitation, fric- tion animal and vegetable life caused effects
 of the same kind as they do now. Nay. even physical astronomy, in so far as it takes us back to the uttermost point of time which
 pathological science can reach, is founded upon the same assumption. If the law of
 gravitation ever failed to be true, even to the
 smallest extent for that period, the calcula-
 tions of the astronomer have no application.
 The power of prediction, of prospective
 prophecy, is that which is commonly regard
 ed as the great prerogative of physical sci
 ence. And truly it is a wonderful fact that
 one can go into shop and buy for small
 price a book-the Nautical Almanacn
 which will foretell the exact position to
 cupied by of Jupiters moons six m.
 hence nay, more, that, if it were wol
 while, the Astronomer Royal could furnish
 us with an infallible prediction applicable to
 1880 or 2980. But astronomy is not less re-
 markable for it's power of retrospective
 prophecy. Thales, oldest of Greek philoso-
 phers, the dates of whose birth and death are
 uncertain, but who hourished about GOO B.
 O., is said to have foretold an eclipse of the
 sun which took place in his timo during a
 battle between the Medes and the Lydians
 Sir George Airy has written very learned
 and interesting memoir, in which he proves
 that such an eclipse was visible in Lydia on
 the afternoon of the 26th of May, in the year
 5S5 B. c. No one doubts, that on that day
 and at the hour mentioned by the Astrono-
 mer Royal, the people of Asia Mino saw the
 face of the sun totally obscured. But, though
 we implicitly believe this retrospective proph-
 ecy, it is incapable of verihcation. It is i'm
 possible even to conceive any means of ascer- taining directly whether the eclipse of Thales happened or not All that can be said is that the prospective prophecies of the astronomer are always verified; and that, inasmuch as his retrospective prophecies are the result of following backward theevery same method as that Whch 1nvar1ably leads to verified results when it is worked forward, there is as much reason for placing full confidence in the one as in the other. Retrospective prophecy is therefore legitimate function of astronomi- cal science; and if it is legitimate for one science it is slegitimate for all; the funda- mental axiom on which it rests, the constan- cy of the order of nature, being the common foundation of all scientific thought Indeed if there can be grades in legitimacy, certain branches of science have the advantage over astronomy, in so far as their retrospect proph- ecies are not only susceptible of verifeation, but are sometimes strihngly verified, Such science exists in that application of the principles of biology to the Interpretation of the animal and vegetable remains imbedded in the rocks which compose the surface of the globe, which is called Paleontoloey. At no very distant time the question whether these so-called 'fossils'' were really the remains of animals and plants was hotly disputed Very learned persons maintained that they were nothing of the kind, but sort of concretion or crystali- zation which had taken place within the stone in which they are found; and which simulated the forms of animal and vegetable life, just as frost on window-pane initiates vegetation. At the present day it would probably be impossible to find any sane advo- cate of this opinion and the fact is rather surprising that among the people from whom the circle-squarers, perpetual -motioners, flat earth men and the like, are recruited, to say nothing of table turner's and spirit-rappers. somebody has not perceived the easy avenue to nonsensical notoriety open to any one who will take up the good old doctrine that fossils are all lusus naturm,