[ printable copy ]
By Stephen D’Arcy
In everyday justifications offered on behalf of contested claims, simply noting that someone once said something about case X offers little or no help in substantiating a claim about case Y, regardless of how esteemed the speaker may have been. For instance, if I want to know how many people live in Greater Manchester today, it is of very little help to cite the remark by Friedrich Engels, in The Condition of the Working-Class in England in 1844 , that Greater Manchester “contains about four hundred thousa