In social psychology, attitudinal theorists propose that in order to understand peoples' opinions, cognitive components and processes must be understood. The current research aims to understand how people take opposing sides when presented with an issue that often provokes controversy: the use of animals for human benefit. We examine: beliefs concerning animals and animal use, empathy toward humans and animals, and value systems. A questionnaire was completed by 177 participants that were allocated to one of three groups: scientists involved with animal use, opponents of animal use, and laypersons. Beliefs concerning animals and animal use, and instrumental and terminal values were ranked in order of importance in order to determine their relative significance. A general measure of attitudes toward the use of animals for medical research was taken, and the Interpersonal Reactivity Index (Davis, 1981) was developed to examine empathy toward humans and animals. Analyses demonstrated that scientists and laypersons differed only on very few measures. These groups presented comparable levels of support for the use of animals in medical research, ranked beliefs and most values in a similar way, and differed on only one of eight measures of empathy. But both groups differed from opponents of animal use on most measures. Factors that best discriminated between these were: belief in animal rights, the benefits of medical research, equality, humans as superior, social recognition, and perceptions of choice. Findings demonstrate that by placing different weighting on either human interests or animal interests, both parties can have a fair understanding of all issues and integrate conflicting ideas, yet hold opposing views on the same topic. This research contributes to the field of human-animal relations, and can inform those interested in the structure, nature and variance in attitudes toward animal use.