Harvey discovered the circulation of the blood, at a time and under circumstances that would surely lead us to expect its immediate acceptance and the hailing of him as a great original thinker in science. He first expounded it to his class, very probably in 1616, which will be remembered as the year of Shakespeare’s death. The glory of the great Elizabethan era in England was not yet passed. Men’s minds had been opened to great advances in every department of thought during the preceding century, by the Renaissance movement and the New Learning in England. Probably no greater group of original thinkers has ever existed than were alive in England during the preceding twenty-five years…What happened is interesting for our purpose. Harvey was so well acquainted with the intolerant temper of men as regards new discoveries, that he hesitated to publish his book on the subject until men had been prepared for it, by his ideas gradually filtering out among the medical profession through the members of his class. He waited nearly fifteen years after his first formal lesson on the subject, before he dared to commit it to print. Shakespeare had made Brutus say to Portia:
“You are my true and honorable wife,
As dear to me as are the ruddy drops
That visit my sad heart;”
but men were not yet ready to accept the great principle of the blood movement. There seems to be good authority for saying that Harvey had more than suspected his great truth for twenty-five years before he dared print it. He realized that it would surely meet with opposition and would make serious unpleasantness between him and his friends. He was not deceived in anticipation. Many of his friends fell away from him, and according to tradition, he lost more than half of his consulting practice, because physicians could not and would not believe that a man who evolved such a strange idea as the constant movement of the blood all over the body, from heart to surface and back, could possibly be in his right mind, and, above all, be a suitable person to consult with in difficult cases.
James J. Walsh, The Popes and Science (1908)