Hugh Blair, answered from the texts and cited to the page.
The preacher's business is persuasion to a course of life, not display and not controversy. The sermon should be grave, unaffected, addressed to conduct, and directed at the understanding and the heart together.12
All pemasion, as I showed formerly, is to be founded on conviction. The understand- ing must always be applied to in the first place, in order to make a lasting impression on the heart: and he who would work on men's passions, or influence their practice, without first giving them just principles, and enlightening their minds, is no better than a mere declaimer.Lectures on Rhetoric and Belles Lettres
To recommend some one grace or virtue, or to inveigh against a particular vice, furnishes a subject not deficient in unity Or precision; but if we confine ourselves to that virtue or vice as assuming a particular aspect, and consider it as it appears in certain characters, or affects certain situations in life, the subject becomes still more interesting.Lectures on Rhetoric and Belles Lettres
Practiced as well as taught, in five volumes of sermons that were read far beyond Scotland.