This blog has complained before about the vogue for mixing fact and fiction so as to blur the distinction between them. On this as on so much else, Johnson has something to contribute.
Talking of an acquaintance of ours, whose narratives, which abounded in curious and interesting topicks, were unhappily found to be very fabulous; I mentioned Lord Mansfield’s having said to me, “Suppose we believe one half of what he tells?” JOHNSON. “Ay; but we don’t know which half to believe. By his lying we lose all reverence for him, but also all comfort in his conversation.” BOSWELL. “May we not take it as amusing fiction?” JOHNSON. “Sir, the misfortune is, that you will insensibly believe as much of it as you incline to believe.”