When we combine our common sense about what animals are like with basic research into what animal circuses are like, it is difficult for intelligent people of moral character to escape engagement with very serious scientific and ethical questions- questions that may become all the more urgent for those who see the concerns of science and ethics as intimately connected within a religious frame of reference.
The scientific question is this: Is it possible for animals like elephants, tigers and chimpanzees physically and psychologically to thrive as performers in a traveling animal circus? While there may be veterinarians on the payroll who answer in the affirmative, the majority of scholarly scientific literature in cognitive ethology strongly suggests otherwise- as a review of the references in any book by Jane Goodall, Jonathan Balcombe, or Marc Bekoff, among many other animal scientists, demonstrates.
The ethical question is this: Is it morally advisable to support an industry that systematically compromises the most basic interests of intelligent, emotional and social creatures merely for the sake of entertaining people? Let us acknowledge that no urgent human need is served by animal circuses, and even no desire to be entertained is served that cannot be adequately met by dozens of other comparable, similarly-priced or cheaper entertainment options that do not require the exploitation of elephants, tigers, chimpanzees and other animals conscripted into circus life. To answer this question in the affirmative is akin to saying that one's trivial desire to be entertained by exploited animals outweighs the most fundamental interests of those animals themselves. Unsurprisingly, the strong consensus among professional animal ethicists working in philosophy, human/animal studies and philosophical theology is that the answer to this question is a resounding no.