It was his principle to excite the attention fully and strongly for a short time, and never to go to the point of fatigue.

...

In the education of the heart, his warmth of approbation and strength of indignation had powerful and salutary influence in touching and developing the affections.

The scorn in his countenance when he heard of any base conduct; the pleasure that lighted up his eyes when he heard of any generous action; the eloquence of his language, and vehemence of his emphasis, commanded the sympathy of all who could see, hear, feel, or understand.

Added to the power of every moral or religious motive, sympathy with the virtuous enthusiasm of those we love and reverence produces a great and salutary effect.
'It often happens that a preceptor appears to have a great influence for a time, and that this power suddenly dissolves.