An essential epistemic consideration is the conditional nature of medical knowledge. This uncertainty must be understood when acquiring new knowledge or designing treatments. We must value all sources of information, neither discarding those deemed lower on the current value scale, nor slavishly accepting randomized clinical trials or their meta-analyses as the fount of all knowledge. Generally, the tension between clinical investigation and individual care can be framed in a utilitarian versus deontologic or rights-based philosophy. The utilitarian is clearly appropriate to public health considerations, but what is learned for public health may not necessarily be in the best interest of an individual patient. In utilitarianism, the distribution of goods-in this case, health-is not important; rather, it is the amount of total good gained that is to be maximized. Too often we assume that survival or cure is a sufficient metric, with no similar quantitative measure of other factors. This often leads to the so-called best treatment being not what the patient wants. All personal care requires consideration of both the helpful and harmful consequences of treatment in the context of individual patient comorbidity, preferences, and fears. Knowledge of patients in general is not what is required; rather, it is how to apply the information to the particular patient that is the heart of medical practice. Each patient's episode of illness is the consequence of a unique interaction of that individual with the disease. Good patient care considers the disease and its management in the context of each patient's values. (C) 2014 by American Society of Clinical Oncology