highlight worrying deficiencies in clinicians' judgments on capacity and consent to treatment (December 2002 JRSM 1). Unfortunately, their summary may further confuse matters by stating that, '15% of all respondents wrongly believed that a competent adult could lawfully be treated against his or her will'. In fact, competent adults can be lawfully treated against their will, in certain clearly defined circumstances. The key omission here is the phrase, 'under common law' (which was included in the question posed to doctors). This was no doubt an oversight, but it draws attention to a related concernnamely, that doctors (and medical students) often seem to conflate judgments about capacity and the common law with judgments about mental disorder and the Mental Health Act, when discussing whether patients can be treated without their consent. In fact such judgments should be clearly distinct. Someone with a mental disorder who is detained under the Act may still meet the capacity criteria (and thereby be judged competent) to consent to, or refuse, certain medical treatments 2. Contrariwise, an individual without a mental disorder may fail to meet the capacity threshold, and be deemed incompetent. Jackson and Warner also found that medical students were very poor at identifying the criteria for capacity, with only 15% doing so correctly. That students are misinformed about issues of medical ethics and law is not surprising. In a recent teaching session, a senior doctor insisted to our group that in England an adult (such as a spouse) could consent to medical treatment on behalf of another adult. Until the teachers are correctly informed about these important issues, what hope for their students?