Negligence and inherent unreasonableness

In Australia, the reduced mental capacity which is characteristic of children alters the standard of care required of them before their behaviour will be judged legally negligent. Seemingly inconsistently, similar incapacity experienced by adults with a mental illness, has generally been regarded as irrelevant to decisions about tortious liability. To date, this has led to few practical consequences, as only a handful of mentally ill defendants have come before the courts in negligence claims. Yet with the ageing population,1 the growing number of people with dementia,2 and the universal policy of deinstitutionalisation, which places those with a mental illness in the wider community, it is likely that areas of law, including tort law, will come to deal more often with defendants suffering from reduced mental capacity.3 This article examines the apparently inconsistent way in which the common law of negligence responds to tortfeasors with reduced mental capacity, and contends that neither courts’ reasons, nor academic analyses provide adequate explanation for this discrepancy. The article provides several proposals for resolving this dissonance