The lecturer should give the audience full reason to believe that all his powers have been exerted for their pleasure and instruction.
“Your senses are reeling all the time. Finally you find something to write and the very next day you go out and see something else which totally contradicts what you've written and every conclusion you've come to.”
“My diminished girth, in tailor phraseology, was hardly conceivable even by my own friends, or my respected medical adviser, until I put on my former clothing, over what I now wear, which is a thoroughly convincing proof of the remarkable change.”