Thou Shalt Not Fear to Repeat Thyself

Thou shalt aim always at clarity of exposition, to which all other literary aims shall be subordinated, remembering the words of the prophet commandant Black, "clarté prime, longueur secondaire." To this end thou shalt strive that no sentence be syntactically capable of any unintended meaning, and that no reader be obliged to read any sentence twice to be sure of its true meaning. To this end also thou shalt not fear to repeat thyself, if clarity require it, nor to state facts which thou thinkest as well known to others as to thyself; for it is better to remind the learned than to leave the unlearned in perplexity.

HUGH TREVOR-ROPER