The theme of the short story "The Tractor" is the environment, and the morality of a variety of responses to it. The dominant issue which is addressed is whether it is right to destroy the natural environment "in the interests of wealth and development", or whether the land should be maintained in perpetuity as it is "in the interests of nature, beauty, and tranquility".
The central question is explored in the experience of two main characters, Ann, an idealistic city denizen and budding naturalist, and Ken, who as a businessman takes pride in his ability to help farmers profit from the sale of their land and to provide citizens with suburban-style houses built on the land the farmers have relinquished. Ann and Ken, who are engaged to be married, must reconcile their very different beliefs and approaches to the idea of the sanctity of the land in order for their relationship to develop.
In developing the central theme of moral responses to the issue of environment, the author outlines a host of difficult questions, but provides few answers. Some questions that he raises include whether the natural environment should be preserved at the expense of those seeking to find housing away from the big cities, the morality of farmers profiting from the sale of their land to housing developers, and the proper response to those "outside the normal social sphere" who would "wreak their individual vengeance on the representatives of social change". The story has been called "a moral fable for modern times"; the author makes it clear that there is no easy answer to the choice between conservation of our earth and its development.