Aliorum medicus, ipse ulceribus scates

   Who boast of curing poor and rich,
   Yet are themselves all over itch.

Physicians pretending to cure the diseases of others, and are themselves loaded with complaints, are the immediate objects of the censure contained in this adage; but it may also be applied to persons railing against vices to which they are themselves addicted. Persons whose office it is instruct the people in the duties of morality and religion, should consider how much their admonitions will lose of their weight and efficacy if their conduct is not in a great degree, at the least, consonant to their doctrine; if they cannot entirely refrain from vice, they should be extremely careful to conceal their deviations from the precepts they mean to inculcate, lest their example should be more powerful than their lectures.