ideas communicated. Considering the operation of this law under these conditions, we find that the thought communicating only, as nearly as may be, the generic idea, will be distinguished from it by the addition of but a single attribute as the generic by itself is incapable of being represented in concrete form, the expression of this thought in form will present us matter distinguished from matter in general by but a single attribute. The least possible individualizing attribute added to the highest possible generalization gives us the simplest expression of an idea, and the form or the organism symbolizing this thought will be the simplest form and the simplest organism possible. For instance: in organic life the highest generalization barely individualized will give us the simple cell; and no matter what degree of complexity we subsequently reach by the addition of an almost infinite number of attributes, we nevertheless begin in every case with the same starting point.

Each higher type is reached by adding to a lower. The higher thus embraces all that can be found in the lower, and something besides. This method is invariable, and can never be departed from. The genus must always be predicable of every individual component of every species contained under it. Translating this law into the forms of material expression, and it requires each higher species to physically include all lower species, and to differ from them only by addition. Man, the highest type, must thus include all the attributes of the cell as physically expressed, and without them he would not be man. The differences between no two terms in a series can be total. If the successive steps in a train of thought must be related, so that no two notions will be wholly distinct from each other, these notions will constitute a series, each term of which will, in a measure, determine the next, so soon as the law of the series is discovered; and if this train of thought be objectively presented, it will afford a corresponding series of physical terms, each one of which will in like manner determine the next. But thought is impossible unless by a train of ideas so related. Its physical expression will therefore be equally impossible except by a series of physical terms similarly related, each one of which in some manner determines the next. There must then be a perfect continuity in the line that reaches from the simplest form of matter through all grades of organic life up to man, the highest expression of the divine idea. There can be no break in the chain of thought, because the law of the logical process forbids it: there can be no break in the series of material symbols for the conditions of concrete expression equally forbid it. A symbol is nothing except as it represents that which is to be symbolized. So the symbols form a physical series, because the thoughts symbolized form a logical series.

If the creator has fully revealed his thought, it must be by a series of physical terms arranged in such a manner as to indicate the logical series of ideas symbolized. Every form of matter is a symbol of thought, and challenges interpretation. Every change in form corresponds to an antecedent change in idea, and must be intended to reveal it. As thought, then, begins its evolution with the general and proceeds to the individual by a series of terms each of which is similarly related to both extremes, we must find the material enunciation of this process assuming the form of a series of terms, beginning with mere nebulous matter, grading into organic life, and organic life presenting us with a similar series beginning with the mere cell and ending with man. So rigid and invariable must this serial arrangement be that if a term in either series be wanting, we are authorized to hypothetically interpolate it.

"Nature never makes a leap," says the scientific investigator, as he studies the material symbols of thought. "Thought never makes a leap," says the metaphysician, as he studies the necessary laws of rational action: and both have uttered the same truth. We prove a proposition by determining the steps by which it was educed from a more generic statement. Science must proceed in the same manner, for science only discovers the track of mind—it does not make the track, it only follows it. If then we find the chain of evolution broken at any point, science must either stop there, or assume the wanting term in the series. We have the right to interpolate these missing terms, for we must assume that the thoughts of God communicated to us in material forms constitute a continuous revelation, beginning with Himself, the final generalization, and ending with man the highest individualization. These limits are fixed—the one by the nature of God, and the other by the nature of man. Between these two extremes we must find a series of intermediate terms. Any other conception of their relation than that of a determinate series is impossible and irrational; and a series, so far as it means anything, means evolution of some sort. Finding the relation between these terms—distinguishing the same which reproduces itself, and the different which introduces a new term—that is, determining the law of apparent evolution—is the problem presented to science.

The astronomer found Bode's law to all appearance violated by the omission of a planet between Mars and Jupiter. He could see no reason for the law, but if the planets had been placed by an intelligent Creator, some order of arrangement must be discoverable according to which their position was determined. The Creator being intelligent, it is impossible to conceive them placed fortuitously. There must then be a link between Mars and Jupiter, because the law once established cannot be broken. The same law may be observed in the arrangement of leaves around the axis of a plant. If intelligence arranged them they must be arranged in some order, for intelligence never performs the least act without a purpose. Each leaf or pair of leaves is not a mere duplication of the previous leaf or pair of leaves. The relation which subsists between any two sets in the series expresses the idea of the Creator, and this must be constant. Completing the series as indicated by different plants, we may assume that if any term is apparently wanting, it is only because it has not been discovered. In neither of these cases would it be asserted that any physical evolution had taken place—the terms form a series of which each term is equally determined by the operation of a fixed law; and yet it is an operation precisely analogous to that which in the case of animals presents every appearance of a real evolution. Take, for instance, a series of animals, presenting at one period of time the simplest and most rudimentary forms, and at another the most complex and highly organized; we cannot do otherwise than conceive these two extremes as related by intermediate terms, through the operation of some law which holds good throughout the series. The relation subsisting between any two, must be the same as that subsisting between any other two similarly situated, or a departure from that relation which is itself governed by a definite law discoverable from a comparison of two sets of terms. The application of this law is so universal and so rigid that we need not hesitate to interpolate a missing term, and confidently assert that it either does exist or has existed. To deny this principle is to deny the necessity of continuity in reasoning. This continuity of thought is represented in matter by the persistence of generic forms under specific differences. But just as the specific is the generic with certain additions, so the individual is this same generic with still further additions; and these additions, whether considered solely in space, as given in the symbols of physical science, or in time as in the conceptions of intellectual science, must