The background of the trial can be narrated briefly. On March 21, 1925, the state of Tennessee passed a law forbidding the teaching of the theory of evolution in publicly supported schools. The language of the law was as follows:
Section 1. Be it enacted by the general assembly of the state of Tennessee, that it shall be unlawful for any teacher in any of the universities, normals and all other public schools of the state, which are supported in whole or in part by the public school funds of the state, to teach any theory that denies the story of the Divine creation of man as taught in the Bible, and to teach instead that man has descended from a lower order of animals.
That same spring John T. Scopes, a young instructor in biology in the high school at Dayton, made an agreement with some local citizens to teach such a theory and to cause himself to be indicted therefor with the object of testing the validity of the law. The indictment was duly returned, and the two sides prepared for the contest. The issue excited the nation as a whole; and the trial drew as opposing counsel Clarence Darrow, the celebrated Chicago lawyer, and William Jennings Bryan, the former political leader and evangelical lecturer.
The remarkable aspect of this trial was that almost from the first the defense, pleading the cause of science, was forced into the role of rhetorician; whereas the prosecution, pleading the cause of the state, clung stubbornly to a dialectical position. This development occurred because the argument of the defense, once the legal technicalities were got over, was that evolution is “true.” The argument of the prosecution was that its teaching was unlawful. These two arguments depend upon rhetoric and dialectic respectively. Because of this circumstance, the famous trial turned into an argument about the orders of knowledge, although this fact was never clearly expressed, if it was ever discerned, by either side, and that is the main subject of our analysis. But before going into the matter of the trial, a slight prologue may be in order.
It is only the first step beyond philosophic naïvete to realize that there are different orders of knowledge, or that not all knowledge is of the same kind of thing. Adler, whose analysis I am satisfied to accept to some extent, distinguishes the orders as follows. First there is the order of facts about existing physical entities. These constitute the simple data of science. Next come the statements which are statements about these facts; these are the propositions or theories of science. Next there come the statements about these statements: “The propositions which these last statements express form a partial universe of discourse which is the body of philosophical opinion.”[24]
To illustrate in sequence: the anatomical measurements of Pithecanthropus erectus would be knowledge of the first order. A theory based on these measurements which placed him in a certain group of related organisms would be knowledge of the second order. A statement about the value or the implications of the theory of this placement would be knowledge of the third order; it would be the judgment of a scientific theory from a dialectical position.
It is at once apparent that the Tennessee “anti-evolution” law was a statement of the third class. That is to say, it was neither a collection of scientific facts, nor a statement about those facts (i.e., a theory or a generalization); it was a statement about a statement (the scientists’ statement) purporting to be based on those facts. It was, to use Adler’s phrase, a philosophical opinion, though expressed in the language of law. Now since the body of philosophical opinion is on a level which surmounts the partial universe of science, how is it possible for the latter ever to refute the former? In short, is there any number of facts, together with generalizations based on facts, which would be sufficient to overcome a dialectical position?
Throughout the trial the defense tended to take the view that science could carry the day just by being scientific. But in doing this, one assumes that there are no points outside the empirical realm from which one can form judgments about science. Science, by this conception, must contain not only its facts, but also the means of its own evaluation, so that the statements about the statements of science are science too.
The published record of the trial runs to approximately three hundred pages, and it would obviously be difficult to present a digest of all that was said. But through a carefully selected series of excerpts, it may be possible to show how blows were traded back and forth from the two positions. The following passages, though not continuous, afford the clearest picture of the dialectical-rhetorical conflict which underlay the entire trial.
The Court (in charging the grand jury)