This article analyzes the ethical perspectives of four technical communication textbooks. It argues that the authors do not engage in ethical inquiry as it is defined traditionally. Instead, they engage in the ethics-related activities known as moral casuistry, which deduces moral judgements, and moralism, which prescribes moral principles. The authors deduce and prescribe, but they do not justify or critically examine the underlying principles of morality. The analysis also suggests that at least two of the textbooks introduce ideas that are either inconsistent with traditional ethical theories or are subject to the objections that philosophers have raised against them in previous ethical inquiries. Finally, the article recommends that authors avoid approaches that are either strictly rhetorical or provide no ethical guidelines for students. They should avoid resorting to cursory accounts of traditional ethical theories because briefly mentioning philosophers' ethical approaches has very little practical value. They should also treat moral principles, not as objective and self-evident statements of fact, but as evaluative assumptions whose truth-values and meaning are both tentative and lacking universal agreement.