Edged tools are dangerous things to handle, and not infrequently do much hurt.
— Agnes Repplier

There is a constant in the average American imagination and taste, for which the past must be preserved and celebrated in full-scale authentic copy; a philosophy of immortality as duplication. It dominates the relation with the self, with the past, not infrequently with the present, always with History and, even, with the European tradition.
— Umberto Eco

First impressions are often the truest, as we find (not infrequently) to our cost, when we have been wheedled out of them by plausible professions or studied actions. A man's look is the work of years; it is stamped on his countenance by the events of his whole life, nay, more, by the hand of nature, and it is not to be got rid of easily.
— William Hazlitt

Thought is a process of exaggeration. The refusal to exaggerate is not infrequently an alibi for the disinclination to think or praise.
— Eric Hoffer

If the reviewing of books be... an ungentle craft, the making of them is, for the most part, a dishonest one -- and that department of literature which ought to be entrusted to those only who are distinguished for their moral qualities is, not infrequently, in the hands of authors totally devoid of good taste, good feeling, and generous sentiment. The writers of Lives have, in our time, assumed a license not enjoyed by their more scrupulous predecessors -- for they interweave the adventures of the living with the memoirs of the dead; and, pretending to portray the peculiarities which sometimes mark the man of genius, they invade the privacy and disturb the peace of his surviving associates.
— John Cam Hobhouse