The lecture discusses the issue of actuarial evidence in personal injury cases, and how the courts have been diffident towards actuarial evidence and the utility and importance of actuarial expertise. Until recently lawyers have not understood the ways in which actuaries work with probabilities. The lecture then shows that now the law has adopted actuarial thinking in several significant ways, and in particular in damages and personal injury cases. The discount rate for calculating the multiplier for future loss is discussed, as is the new area of risk assessment and conditional fees. Lawyers need actuarial help where appropriate, and both face the daily problem of applying the laws of probability to human activity.