Hugh LaFollette

_The Practice of Ethics_ is an outstanding guide to the burgeoning field of applied ethics, and offers a coherent narrative that is both theoretically and pragmatically grounded for framing practical issues. Discusses a broad range of contemporary issues such as racism, euthanasia, animal rights, and gun control. Argues that ethics must be put into practice in order to be effective. Draws upon relevant insights from history, psychology, sociology, law and biology, as well as philosophy. An excellent companion to LaFollette's authoritative anthology, _Ethics in Practice: An Anthology, Third Edition_

In this article we discuss two divergent accounts of non-human animals as analog models of human biomedical phenomena. Using a classical account of analogical reasoning, toxicologists and teratologists claim that if the model and subject modeled are substantially similar, then test results in non-human animals are likely applicable to humans. However, the same toxicologists report that different species often react very differently to the same chemical stimuli. The best way to understand their findings is to abandon the classical view of analogical - i.e., linear - reasoning, and replace it with a version informed by chaos theory. We briefly outline the current understanding of chaos, and trace its implications for toxicology and teratology.