Let me offer a counterpoint, which may help in formulating your thoughts. In particular I want to challenge the notion that there will always be progress. I think we have been influenced by Darwin's theory of evolution for too long. So, let me begin with a question:
How does one know that there will always be progress? Does not history shows that there are times of stagnation and regression? For example, all empires rise and fall, certain things are learned, forgotten and relearned. Some things may have been forgotten and never relearned. As Peter Berger, the sociologist, says, “It is also possible that there was a secret conclave of Aztec priest who knew something we have not even dreamed of – and that this truth perished with them, never to be recovered.” More importantly, how should one even define progress? In the least, one should question the notion of continual progression.
There are several questions that have to be addressed here. Society progresses through the power of thought, according to the play. In this regard, Drummond's line is a powerful one: "He wishes to be a sponge." The critical element in terms of social progress, as defined by Drummond, is the ability for individuals to think and critically evaluate truths for themselves. This is contrasted to Brady, who believes that society progresses through its faith and zeal in God. The basic premise in the play is that both notions of the good are in competition with one another. As the play progresses, the reader understands that Brady has come to a point where the advancement of society encompasses the ability for individuals to decide for themselves who they are and how they shall live. This can integrate both spirituality and ability to believe in scientific thought. The theme of the work ends up becoming this critical element. Through discourse and discussion, individuals can better understand their own sense of self and the notion of social betterment.