An History of Magic, Witchcraft, and Animal Magnetism, Vol. 1

and a particular habit of thinking, according to a common proverb, becomes a second nature:

“Ponere difficile est quæ placuere diu.” It is difficult to set aside what has long been pleasing.

If we look back over the ages that have passed, we will likely find that a considerable number of the obstacles to the introduction of new truths generally arise from the specific direction given to inquiry by the previous speculations of otherwise distinguished men. New discoveries in every succeeding age may conflict with some of the opinions and dogmas, or even the prejudices, of the learned men of their time; and the learned—or those reputed to be learned—have, at all times, been the most stubborn opponents of new truths.

“Turpe putant parere minoribus, et quæ
Imberbes didicere, senes perdenda fateri.” They think it shameful to yield to their juniors, and to confess as old men that what they learned as beardless youths must now be discarded.

In the investigation of nature, indeed, it is a very difficult thing to shake off preconceived notions—to maintain the clarity and unbiased impartiality of our judgment, and to avoid being misled by our prejudices. It is almost unnecessary to remind our readers of the well-known examples of GALILEO, COLUMBUS, HARVEY, JENNER, etc., or to expand upon the opposition made to the introduction of Inoculation, Quinquina Cinchona bark, used to treat malaria., Antimony, etc.,