And if we believe that Creation was a progressive act, it is rather probable than otherwise that such interferences should take place. For a long period perhaps the uniformity of the work might lead us to forget the Being who was working; but times would arrive when definite stages of the work were accomplished, when higher developments of being were rendered possible, and in the introduction of those higher developments a something would be seen which could not be the result of the processes with which we had already become acquainted. Such interference would not in any way justify the supposition that the designs of the Author of Nature were changed, or that His original plan had proved defective. The more natural inference would be that they were a part of the plan from the first, but that the time for them was not then come. It will be seen in the sequel that in all probability many of the special acts of Creation, mentioned in the Mosaic Record, are interferences of this kind; that for long periods of time matters advanced in a uniform manner; that the sequence of events was such as our own experience would lead us to anticipate; but that these periods were separated from one another by the introduction of new forces and new results. Of the former we may speak then as carried on under the operation of natural laws; the other may be described as special interferences not antagonistic, but supplementary, to natural laws, and forming part of the original design. SECTION 2. THE CORRELATION OF FORCES. [Footnote: For fuller information on this subject, Grove's "Correlation of the Physical Forces," or Tyndall's "Lectures on Heat considered as a Mode of Motion," may be consulted.]