not only is an enormous period required for the slow development of man from the brute, but corresponding periods must have been consumed in the production of each link of the long chain of which he is the culmination. The time demanded by some forms of the uniformitarian geology had already confounded the imagination; but Mr. Darwin required it to be multiplied, and now we find Mr. Huxley suggesting, in a passage already referred to, that even this is insufficient, and that, "if any form of the doctrine of progressive development is correct, we must extend by long epochs the most liberal estimate that has yet been made of the antiquity of man." This is doubtless true, and, in its truth, will be found to require a proportional enlargement of the periods of all earlier links in the chain. But may there not be some limits to the past duration of the earth, in approximately its present form, inconsistent with such vast demands? There are facts in regard to the retardation of the rotation of the earth upon its axis, to the gradual exhaustion of the supply of heat from the sun, and to the secular cooling of the earth, which, if fully understood, would supply some tolerably definite data for a calculation of the age of the existing state of our cosmos. At present these facts are imperfectly investigated, so that the calculation of the maximum duration possible can only be made with a very large margin of probable future reduction. Sir W. Thomson has made these calculations with great care, and, in several papers noted below, has given his conclusions to the world. There are three lines of argument. That on the age of the sun's heat is the most vague, from the imperfection of the data. Still, such conclusions as can be reached are sufficiently in accordance with the results obtained in the other lines. The

1 On the Age of the Sun's heat. By Sir W. Thomson. Macmillian's Magazine, 1862. On the Secular Cooling of the Earth. By the same. Trans. R.S.E., 1862, and Philosophical Magazine, 1863, ii. The Uniformitarian Theory of Geology briefly refuted. By the same. Proc. R.S.E., 1865. On Geological Time. By the same. Transactions of the Geological Society, of Glasgow, 1868. Of Geological Dynamics. By the same. Transactions of the Geological Society of Glasgow, 1869.

argument from the retardation of the revolution of the earth upon its axis, taken in connection with the oblateness of its spheroid, points to a hundred million of years as the utmost limit of time within which the earth must have assumed its present form. More exact observation of the data may, and probably will, enormously reduce this limit; but there it stands at present, if the mathematician can be trusted, as the outside boundary of geologic time. Mr. Huxley, notwithstanding what he has elsewhere said, in his Presidential Address to the Geological Society of London, in 1869, professes his willingness to accept the limitation, especially if it be taken with such a degree of elasticity as to allow of its being stretched two or threefold; but even this is obviously felt as a serious and objectionable restraint by the advocates. of Darwinism. Mr. Darwin himself has claimed, in his 'Origin of Species," "that, in all probability, a far longer period than three hundred million years has elapsed since the latter part of the secondary period." But demands for vast and practically boundless time are too familiar to the readers of this class of works to require quotation.

66

Sir W. Thomson's third line of argument, drawn from the time required for the cooling of the earth from a molten mass, still leads substantially to the same conclusion, although indicating a considerably inferior limit for the date of the introduction to our earth of any known form of organic life. There is here put in, it is true, in arrest of judgment — a sort of perpetual-motion theory of chemical action, by Sir C. Lyell, to account for the internal heat of the earth; but it does not seem sufficiently tenable to require consideration. It remains that all these lines of mathematical calculation converge to a limit for the whole, far within that which Mr. Darwin has claimed as probably too small for a mere fraction of geologic time.

But we have already exceeded our limits. The following is the list of charges brought forward against Darwinism by Mr. Mivart, who fully commits himself to the general theory of evolution: "That natural selection' is incompetent to

account for the incipient stages of useful structures. That it does not harmonize with the co-existence of closely similar structures of diverse origin. That there are grounds for thinking that specific differences may be developed suddenly instead of gradually. That the opinion that species have definite, though very different, limits to their variability is still tenable. That certain fossil transitional forms are absent which might have been expected to be present. That some facts of geographical distribution supplement other difficulties. That the objection drawn from the physiological difference between 'species' and 'races' still exists unrefuted. That there are many remarkable phenomena in organic forms upon which 'natural selection' throws no light whatever; but the explanations of which, if they could be attained, might throw light upon specific organization." 1 Other at least equally serious difficulties are brought forward incidentally in the body of the work.

Mr. Chauncy Wright, in a late (July, 1871) number of the North American has replied to Mr. Mivart; but the reply is to our mind insufficient. We do not intend, however, now to discuss either Mr. Wright's or Mr. Mivart's arguments. The palpable fact, which stands boldly out from this, as from all other repetitions of the discussion, is that Mr. Darwin's theories are simply theories. They may be more or less plausible; they may be met by more or less of objection; and these objections may be more or less perfectly answered. It remains that they are theories; they do not rest upon positive evidence.

If the propounding of such theories can be of advantage to the progress of human knowledge, by all means let them be propounded. Only let it be remembered that there are subjects on which natural science is incompetent to pronounce an opinion, because they lie outside of the range of its investigation. Yet truths may there be firmly established by their own appropriate evidence which are not without an important bearing even upon the studies of the naturalist. Froude well says: "There is no proof such as will satisfy

1 Genesis of Species. By St. George Mivart, F.R.S. Close of chap. i.

the scientific inquirer that there is any such thing as moral truth-any such thing as absolute right and wrong at all.”1 Above all, we ask that the biologist and the physicist alike may not so narrow their investigations of natural phenomena and their relations as to exclude from view the positive and stupendous evidence in nature, in history, and in revelation, of an intelligent Force, external and superior to the natural forces, constituting, guiding, and himself the Final Cause of all.

ARTICLE III.

WHAT IS TRUTH??

BY J. C. MURPHY, LL.D., T.C.D., PROFESSOR OF HEBREW, BELFAST, IRELAND.

A BRIEF answer to this comprehensive question may not be unseasonable at the present time, even though it may be expected to partake in some measure of the idiosyncrasy of the respondent. We misunderstand one another very often, simply because we do not speak out, frankly and plainly, what we think. Let us divest the question of the technicalities of the schools, treat it as a matter of vital interest to every child of man, and endeavor to find at least the first principles of a direct, explicit, and veritable reply. The question came, at first, from a strange quarter, whence we should least of all have expected any reference to things so high. But we bear in mind that Pilate had the rare advantage of coming into contact with a perfect mind - the mind of him who had come down from heaven to solve this very problem, to give a new turn to the philosophy of man, and to open up to the mind of humanity a new, practical, and hopeful view of the relation of God to man. Pilate said to this wonderful visitor of our nether sphere: "Art thou the 1 Short Studies on Great Subjects. Times of Erasmus and Luther, Lect. iii. p. 97.

2 This paper is the expansion of a thought thrown out in the Preface to a forthcoming work on Leviticus.

king of the Jews?" His prisoner replied: "My kingdom is not of this world." Pilate rejoined: "Art thou a king, then?" The stranger then said: "I am a King. To this end am I born, and to this end am I come into the world, that I may bear witness of the truth. Every one that is of the truth heareth my voice." Thus we find that Pilate's mind was raised, for the moment, to the contemplation of this great question, by being thrown into converse with the eternal Son of God, now born of a woman and come into the world for the express purpose of giving a practical answer to this very question. Pilate, the spokesman of the fourth and last world-monarchy, now stands face to face with the eternal King of that fifth monarchy which shall not be moved, whose wand of spiritual power is the truth, and in profound bewilderment of mind puts the natural question: WHAT IS TRUTH?

2. It is manifest that we must arrive at some one general governing principle, if we are to shape an adequate answer in any brief compass to this momentous question. Every fact, every art or science, every chapter of history, is part of the complex answer to this inquiry in its most unlimited range. But all the arts and sciences of the physical world form only a subordinate part of the great system of things. The history of man and the phases of the human mind yield the materials of that metaphysical science which is the sublimest theme that can engage the attention of man. Mind surpasses matter. But even in the study of the mind there is a lower and a higher stage. The philosophy of the intellectual and potential is secondary in importance to the philosophy of the ethical faculty in man. And in the realm of ethics the relation of man to God infinitely transcends his moral relation to his fellow-men. Thus we have reached our governing principle. What is the moral relation of man to God in the present condition of things? This is the theme to which we are to bend our minds, when we propose to make a brief fundamental reply to the all-embracing question, What is truth? All other existing relations are