How has medicine approached difference?
If we first look to the rules guiding and governing medical education, the LCME - Liaison Committee on Medical Education (ED 21 and ED 22) accreditation standards show a need for medical schools to educate about difference:
ED-21. The faculty and students must demonstrate an understanding of the manner in which people of diverse cultures and belief systems perceive health and illness and respond to various symptoms, diseases, and treatments.
All instruction should stress the need for students to be concerned with the total medical needs of their patients and the effects that social and cultural circumstances have on their health. To demonstrate compliance with this standard, schools should be able to document objectives relating to the development of skills in cultural competence, indicate where in the curriculum students are exposed to such material, and demonstrate the extent to which the objectives are being achieved.
ED-22. Medical students must learn to recognize and appropriately address gender and cultural biases in themselves and others, and in the process of health care delivery.
The objectives for clinical instruction should include student understanding of demographic influences on health care quality and effectiveness, such as racial and ethnic disparities in the diagnosis and treatment of diseases. The objectives should also address the need for self-awareness among students regarding any personal biases in their approach to health care delivery.
There is much variation in the way and extent to which these standards are met and evaluated.  There are also challenges in respecting the personal perspective of a student and also evaluating the ability of that student to practice in a manner respectful of difference. The need for evaluation methods that are unbiased is essential.
Medicine has a taken a variety of approaches to educating for an understanding of difference, one of which is ’cultural competence’.
Cultural competence has been defined as:
"A set of congruent behaviours, attitudes and policies that come together as a system, agency or among professionals and enable that system, agency or those professionals to work effectively in cross-cultural situations. The word "culture" is used because it implies the integrated pattern of human thoughts, communications, actions, customs, beliefs, values and institutions of a racial, ethnic, religious or social group. The word competence is used because it implies having a capacity to function effectively."
Are you culturally competent? Take the Quality and Culture Quiz.
Michael Paasche-Orlow states that "culturally competent care is a moral good that emerges from an ethical commitment to patient autonomy and justice." He proposes that the essential principles of cultural competence are: 
acknowledgement of the importance of culture in people’s lives
respect for cultural differences
minimization of any negative consequences of cultural differences
Understanding cultural competence in this way may help us to create a medical climate that is "based on a philosophy of personal in-depth engagement" and embraces pluralism. This sort of medicine not only respects patient autonomy, it assumes it, without assumption that the patient will share the perspective of the provider.
Cultural competence will include a knowledge of other cultures but more importantly, it implies that one is aware of ONE’S OWN biases and prejudices.
To really practice in this way we need to be aware of not only our own cultural norms and ideas, but those of the patient and our society. To this we must also add the values of medicine.
Some aspects of culture are so deeply embedded that they are taken as assumptions and rarely questioned.
1. Liaison Committee on Medical Education. Functions and Structure of a Medical School: Standards for Accreditation of Medical Education Programmes Leading to the MD Degree. 2006. http://www.lcme.org/ specific objectives Ed 21 and 22: http://www.lcme.org/functionslist.htm#educational%20objectives accessed November 20, 2006
4. Cross TL, Bazron BJ, Dennis KW, Isaacs MR. Towards a Culturally Competent System of Care: Vol. I. Washington, DC: National Technical Assistance Center for Children’s Mental Health, Georgetown University Child Development Center; 1989.
6. For an exploration of culture and medical care, read The Spirit Catches You and You Fall Down by Anne Fadiman. Book website: http://www.spiritcatchesyou.com/ Hmongnet book review: http://www.hmongnet.org/publications/spirit_review.html New York Times book review: http://www.nytimes.com/books/97/10/19/reviews/971019.19konnert.html