His response to the first of these questions constitutes what may be called an aprioristic refutation of the orthodox view, by placing the evolutionary palæontologist in the trilemma: (a) of making the awkward confession that, except within limited local areas, he has no means whatever of distinguishing between a geographical distribution of coëval fossil forms among various habitats and a chronological distribution of fossils among sediments deposited at different times; (b) or of denying the possibility of geographical distribution in the past, by claiming dogmatically that the world during Cambrian times, for example, was totally unlike the modern world, of which alone we have experimental knowledge, inasmuch as it was then destitute of zoölogical provinces, districts, zones, and other habitats peculiar to various types of fauna, so that the whole world formed but one grand habitat, extending over land and sea, for a limited group of organisms made up exclusively of the lower types of life; (c) or of reviving the discredited onion-coat theory of Abraham Werner under a revised biological form, which asserts that the whole globe is enveloped with fossiliferous rather than mineral strata, whose order of succession being everywhere the same enables us to discriminate with precision and certainty between cases of distribution in time and cases of distribution in space.
In his response to the second question, Professor Price adduces numerous factual arguments, which show that the invariable order of sequence postulated by the theory of the time-value of index fossils, not only finds no confirmation in the actual or concrete sequences of fossiliferous rocks, but is often directly contradicted thereby. “Older” rocks may occur above “younger” rocks, the “youngest” may occur in immediate succession to the “oldest,” Tertiary rocks may be crystalline, consolidated, and “old in appearance,” while Cambrian and even pre-Cambrian rocks sometimes occur in a soft, incoherent condition, that gives them the physical appearance of being as young as Pleistocene formations. These exceptions and objections to the “invariable order” of the fossiliferous strata accumulate from day to day, and it is only by means of Procrustean tactics of the most drastic sort that the facts can be brought into any semblance of harmony with the current dogmas, which base geology upon evolution rather than evolution upon geology.
Price, then, proposes for serious consideration the possibility that Cretaceous dinosaurs and even Tertiary mammals may have been living on the land at the same time that the Cambrian graptolites and trilobites were living in the seas. “Who,” he exclaims, “will have the hardihood, the real dogmatism to affirm in a serious way that Cambrian animals and seaweeds were for a long time the only forms of life existing anywhere on earth?” Should we, nevertheless, make bold enough to aver that for countless centuries a mere few of the lower forms of life monopolized our globe, as one universal habitat unpartitioned into particular biological provinces or zones, we are thereupon confronted with two equally unwelcome alternatives. We must either fly in the face of experience and legitimate induction by denying the existence in the past of anything analogous to our present-day geographical distribution of plants and animals into various biological provinces, or be prepared to show by what infallible criterion we are enabled to distinguish between synchronously deposited formations indicative of a geographical distribution according to regional diversity, and consecutively deposited formations indicative of comparative antiquity.
The former alternative does not merit any consideration whatever. The latter, as we shall presently see, involves us in an assumption, for which no defense either aprioristic or factual is available. We can, indeed, distinguish between spatial, and temporal, distribution within the narrow limits of a single locality by using the criterion of superposition; for in regions of outcrop, where one sedimentary rock overlies another, the obvious presumption is that the upper rock was deposited at a later date than the lower rock. But the criterion of superposition is not available for the correlation of strata in localities so distant from each other that no physical evidence of stratigraphic continuity is discernible. Moreover the induction, which projects any local order of stratigraphical sequence into far distant localities on the sole basis of fossil taxonomy, is logically unsound and leads to conclusions at variance with the actual facts. Hence the alleged time-value of index fossils becomes essentially problematic, and affords no basis whatever for scientific certainty.
As previously stated, the sequence of strata is visible only in regions of outcrop, and nowhere are we able to see more than mere parts of two or, at most, three systems associated together in a single locality. Moreover, each set of beds is of limited areal extent, and the limits are frequently visible to the eye of the observer. In any case, their visible extent is necessarily limited. It is impossible, therefore, to correlate the strata of one continent with those of another continent by tracing stratigraphic continuity. Hence, in comparing particular horizons of various ages and in distinguishing them from other horizons over large areas, we are obliged to substitute induction for direct observation. Scientific induction, however, is only valid when it rests upon some universal uniformity or invariable sequence of nature. Hence, to be specific, the assumption that the time-scale based on the European classification of fossiliferous strata is applicable to the entire globe as a whole, is based on the further assumption that we are sure of the universality of fossiliferous stratification over the face of the earth, and that, as a matter of fact, fossils are always and everywhere found in the same order of invariable sequence.
But this is tantamount to reviving, under what Spencer calls “a transcendental form,” the exploded “onion-coat” hypothesis of Werner (1749-1817). Werner conceived the terrestrial globe as encircled with successive mineral envelopes, basing his scheme of universal stratification upon that order of sequence among rocks, which he had observed within the narrow confines of his native district in Germany. His hypothesis, after leading many scientists astray, was ultimately discredited and laughed out of existence. For it finally became evident to all observers that Werner’s scheme did not fit the facts, and men were able to witness with their own eyes the simultaneous deposition, in separate localities, of sediments which differed radically in their mineral contents and texture. Thus it came to pass that this classification of strata according to their mineral nature and physical appearance lost all value as an absolute time-scale, while the theory itself was relegated to the status of a curious and amusing episode in the history of scientific fiascos.
Thanks, however, to Wm. Smith and to Cuvier, the discarded onion-coat hypothesis did not perish utterly, but was rehabilitated and bequeathed to us in a new and more subtle form. Werner’s fundamental idea of the universality of a given kind of deposit was retained, but his mineral strata were replaced by fossiliferous strata, the lithological onion-coats of Werner being superseded by the biological onion-coats of our modern theory. The geologist of today discounts physical appearance, and classifies strata according to their fossil, rather than their mineral, contents, but he stands committed to the same old postulate of universal deposits. He has no hesitation in synchronizing such widely-scattered formations as the Devonian deposits of New York State, England, Germany, and South America. He pieces them all together as parts of a single system of rocks. He has no misgiving as to the universal applicability of the European scheme of stratigraphic classification, but assures us, in the words of the geologist, Wm. B. Scott, that: “Even the minuter divisions, the subdivisions and zones of the European Jura, are applicable to the classification of the South American beds.” (“Introduction to Geology,” p. 681f.) The limestone and sandstone strata of Werner are now things of the past, but, in their stead, we have, to quote the criticism of Herbert Spencer, “groups of formations which everywhere succeed each other in a given order, and are severally everywhere of the same age. Though it may not be asserted that these successive systems are universal, yet it seems to be tacitly assumed that they are so.... Though probably no competent geologist would contend that the European classification of strata is applicable to the globe as a whole, yet most, if not all geologists, write as though it were so.... Must we not say that though the onion-coat hypothesis is dead, its spirit is traceable, under a transcendental form, even in the conclusions of its antagonists.” (“Illustrations of Universal Progress,” pp. 329-380, ed. of 1890.)
But overlooking, for the moment, the mechanical absurdity involved in the notion of a regular succession of universal layers of sediment, and conceding, for the sake of argument, that the substitution of fossiliferous, for lithological, strata may conceivably have remedied the defects of Werner’s geological time-scale, let us confine ourselves to the one question, which, after all, is of prime importance, whether, namely, without the aid of Procrustean tactics, the actual facts of geology can be brought into alignment with the doctrine of an invariable order of succession among fossil types, and its sequel, the intrinsic time-value of index fossils. The question, in other words, is whether or not a reliable time-scale can be based on the facts of fossiliferous stratification as they are observed to exist in the concrete. Price’s answer is negative, and he formulates several empirical laws to express the concrete facts, on which he bases his contention. The laws and facts to which he appeals may be summarized as follows:
1. The concrete facts of geology do not warrant our singling out any fossiliferous deposit as unquestionably the oldest, and hence we have no reliable starting-point for our time-scale, because:
(a) We may lay it down as an empirical law that “any kind of fossiliferous rock (even the ‘youngest’), that is, strata belonging to any of the systems or other subdivisions, may rest directly upon the Archæan or primitive crystalline rocks, without any other so-called ‘younger’ strata intervening; also these rocks, Permian, Cretaceous, Tertiary, or whatever thus reposing directly on the Archæan may be themselves crystalline or wholly metamorphic in texture. And this applies not alone to small points of contact, but to large areas.”