as shall adjust it to new scientific theories. We may sum up his views in two or three easily remembered sentences. (1) Do not make scientific difficulties for the sake of adjusting Scripture to them. The conservation of religious feeling is of so much value that it is a crime to disturb it wantonly, or before there is a tolerably clear case of necessity. (2) Face the difficulties manfully when they appear, and show the same candor in your treatment of scientific men that you would ask them to exhibit to you. Both theologians and men of science should remember, as Kepler says, that "it is for their common advantage to conciliate the finger and the tongue of God - his works and his word." 1 There is great loss in unreasonably delaying the concessions which biblical interpreters must from time to time make to science.

The proofs of an external revelation must be considered by inductive philosophers. To assume that religious belief and scientific induction are totally diverse in their character is an unpardonable error; for the same principles of reasoning are employed in forming the one which come into play in securing the other. Scientific induction cannot take the reasoner beyond the realm of faith, and the hopes of religion spring out of a legitimate scientific induction.

1 Quoted by Whewell, Philosophy of the Inductive Sciences, Vol. ii. p. 153.

We are confident that the present bent of the scientific mind is peculiarly favorable to that style of reasoning by which the credibility and authority of the Bible have been established. In its efforts to account for the origin of species, science is taking a higher aim than has heretofore been seriously maintained by any large number of her votaries. Scientific men now strive to do far more than observe and classify. They seek the deeper meaning of the facts which they observe, and are endeavoring to trace out the bond of order which all believe to reign supreme in nature. This kind of intellectual endeavor is congenial to the theological mind. Because, therefore, the work is both important and appropriate we make bold to enter the arena.

There is constantly danger of misunderstanding arising between the students of nature and the interpreters of the Bible. They who should dwell together in peace are too often at war with one another. It is our purpose to mediate between these parties, to show how asperities may be avoided, to illustrate the principles of reasoning which both hold in common, and more definitely to mark out the provinces in which each may have undisputed sway.

In another treatise we have examined the basis of facts upon which the structure of Christian

faith is reared.1 The unity of method pervading our reasoning upon both science and religion will now be shown to best advantage by drawing out at some length, for purposes of comparison, the arguments by which a widely accepted scientific theory is supported.

Not long ago naturalists and theologians were in a heated discussion over the "Unity of the Human Race." The doctrine of the immutability of species was pushed by some to such an extreme that they declared it incredible that the different races of men could have descended from a single pair. Professor Agassiz was an advocate of this view; and to a former generation his name was a terror to orthodox interpreters of the Bible. Even in 1872 Dr. Charles Hodge made the assertion that the unity of the human race is denied by "a large and increasing class of scientific men." 2 It would gratify a good deal of curiosity if the learned doctor had informed his readers from what ranks this "large class of scientific men," who disbelieve in the unity of the human race, is receiving so many recruits; for it seems to appear on the face of almost all recent works scientifically treating the subject of vegetable or animal life, that the question of the day is not whether the human

1 See the author's Logic of Christian Evidences. Andover : Warren F. Draper. 1880.

2 Systematic Theology, Vol. ii. p. 77.

races are of common origin, but whether the whole animal kingdom may not have descended in unbroken lines from one progenitor.

II. Definition of Species.

In approaching the question which of late years has so deeply agitated the students of natural history, it is necessary first to ask, What is a Species ? Indeed, the whole discussion of the Darwinian theory has reference to the meaning of this ambiguous and ill-defined word.

With the objects immediately before us it probably would not be best to plunge deeply into the philosophical mazes opened by the discussions concerning nominalism and realism, though, in fact, these mediaeval mysteries are more closely related to modern scientific theories than is generally supposed. For example, a prominent question, involved in the study of natural history, has always been, What part does inheritance play in giving to individuals that degree of likeness which constitutes them one species? The ordinary answer has been that the points of likeness which characterize a species are the result of the law of inheritance; while the differences which constitute varieties and sub-varieties are the result of the action of the diverse conditions of existence. Upon inspecting the definitions of naturalists it will be seen that the question of the

derivative origin of species turns upon the theories entertained concerning the reality of secondary causes, and upon the prevailing conception respecting the Creator's relation to the universe. Is God's relation to nature immanent or transcendent? Is there a connection of physical causation between the successive phenomena of nature, or is the succession momentarily dependent upon the will of the Creator? God is the first cause of all things, the good of being is the final cause; is there between these a real mechanism of secondary causes, or is there only the semblance of such a mechanism?

The definition of species given by Professor Dana is sufficiently realistic. "A species among living beings, as well as inorganic, is based on a specific amount or condition of concentred force defined in the act or law of creation," i.e. a species is a real unfolding of a real force, and by whatever act or law of creation defined, is the realization of a well-defined divine idea. But even this definition, distinct as it is in recognizing the creative act which is the initiatory cause of the species, does not determine the mode through which the creative impulse reaches its realization in natural forms. For anything given in this definition, it may be supposed that the forces which became at last permanently concentred into the specific forms of life, 1 See Bibliotheca Sacra, Vol. xiv. p. 861.