408 BIOLOGY AND ITS MAKERS 
naturalists upon the distinguishing features of the particular 
kinds of animals and plants. Are species realities in nature ? 
The consideration of this apparently simple question soon. 
led to divergent views, and then to warm controversies that 
extended over several decades of time. 
The view first adopted without much thought and as a 
matter of course was that species are fixed and constant; 2.e., 
that the existing forms of animals and plants are the descend- 
ants of entirely similar parents that were originally created 
in pairs. Thisidea of the fixity of species was elevated to the 
position of a dogma in science as well as in theology. The 
opposing view, that species are changeable, arose in the 
minds of a few independent observers and thinkers, and, as 
has already been pointed out, the discussion of this question 
resulted ultimately in a complete change of view regarding 
nature and man’s relation to it. When the conception of 
evolution came upon the scene, it was violently combated. 
It came into conflict with the theory designated special 
creation. 
Views of Certain Fathers of the Church.—-And now it is 
essential that we should be clear as to the sources of this 
dogma of special creation. It is perhaps natural to assume 
that there was a conflict existing between natural science 
and the views of the theologians from the earliest times; 
that is, between the scientific method and the method of the 
theologians, the latter being based on authority, and the 
former upon observation and experiment. Although there 
is a conflict between these two methods, there nevertheless 
was a long period in which many of the leading theological 
thinkers were in harmony with the men of science with refer- 
ence to their general conclusions regarding creation. Some 
of the early Fathers of the Church exhibited a broader and 
more scientific spirit than their successors. 
St. Augustine (353-430), in the fifth century, was the 
