There are three ways in which a statement, especially a disputable statement, can be placed before mankind. The first is to assert it by avowed authority; this is done by deities, the priests of deities, oracles, minor poets, parents and guardians, and men who have “a message to their age”. The second way is to prove it by reason; this was done by the mediaeval schoolmen, and by some of the early and comparatively forgotten men of science. It is now quite abandoned. The third method is this: when you have neither the courage to assert a thing nor the capacity to prove it, you allude to it in a light and airy style, as if somebody else had asserted and proved it already.
Source: The Illustrated London News (7 Aug 1909)