Religion and science seem as if they are opposing forces in the novel, and yet a person like Ira Hinkley lives between both of these forces. Also, both Gottlieb and Martin are seen "praying" in their own ways. Religion requires faith and science requires doubt. Still both of these entities (religion and science) are belief systems, which is what, paradoxically, makes them so similar in their opposition.
There is no doubt that Lewis is criticizing the overzealous Christians like Ira Hinkley, who, in their arrogance and extremes, diminish in the eyes of the viewer. And yet, it is important to realize that the overzealous scientist is also reduced in the novel: Gottlieb ends in a poor and senile state. There are no real conclusions to draw from the opposition of religion and science throughout only that they are similar in their capacities for extremes and in their power. Also, it becomes important that the scientist accept this struggle just as he must accept all the other struggles that exist in his "plight."
Men like Holabird and Tubbs (and the sector of the medical world they represent) seem "happy," and yet they are what Martin calls "Men of Measured Merriment." Martin believes that their happiness is measured because it is the happiness that comes with social success and the profits reaped in "business," not Martin's ideal for greatness and discovery. The happiness that comes out of a superficial success does not compare, for Martin, to the solitary success of discovering something that may become a cure or that may help in the search for fundamental understandings. And thus, these "machines," as Martin implies that they are, are measured in their happiness, just as they are measured in everything they do in life. They are proper, correct, successful, and rich—they are everything they are "supposed" to be and yet they are hypocritical and often times dangerous to Martin and others' own search for "truth."
Gottlieb tells Martin that he will be lucky if he is not successful because success ruins the scientist. Success would diminish the laboratory scientist to the level of the "men of measured merriment." To insult Martin, Gottlieb calls him a "college president" among other things, illustrating his contempt for "success." The greatest reason for this contempt is that it is a temptation from ones true calling. This is, of course, another element of Lewis's romance and is comparable to the painter or writer that writes magical verse or creates masterpieces on canvas but never sells a line or stroke and dies in poverty with their greatness unknown to man.