Poisoning the well (or attempting to poison the well) is a fallacy where adverse information about a target is preemptively presented to an audience, with the intention of discrediting or ridiculing everything that the target person is about to say. Poisoning the well can be a special case of argumentum ad hominem, and the term was first used with this sense by John Henry Newman in his work Apologia Pro Vita Sua (1864). The origin of the term lies in well poisoning, an ancient wartime practice of pouring poison into sources of fresh water before an invading army, to diminish the attacking army's strength.