In many cases the approach and techniques of the complementary therapies have a scientific basis. This is particularly true for aromatherapy using essential oils extracted from plants. Aromatherapy is scientific in terms of the biochemical and physiological functioning of the body and works in conjunction with the more esoteric and spiritual needs of the individual. It is naive and dangerous to dismiss science as bad and separate from our use of natural materials. A dictionary definition of science is ‘the systematic study of the nature and behaviour of the material and physical universe, based on observation, experiment and measurement’. Scientific findings are ‘a body of knowledge organized in a systematic manner’. To be credible and effective, both conventional and complementary medicine must adopt a scientific approach delivered with care and insight.