IN his Harveian Oration delivered before the Royal College of Physicians on October 19 and published in the British Medical Journal of October 24, Sir Walter Langdon-Brown, emeritus professor of physic in the University of Cambridge, described the background to Harvey as represented by contemporary thought, of which Francis Bacon, Robert Burton, the author of “The Anatomy of Melancholy”, John Donne, the Dean of St. Paul's, Sir Thomas Browne, Thomas Hobbes, the author of “Leviathan”, and the Cambridge Platonists were the chief exponents. Like Sir William Hale-White in his Harveian Oration of 1927, Sir Walter maintained that the “Novum Organum”, in which the new spirit of England found its clearest expression, had a deep influence on the mind of Harvey who, as his medical adviser, came in close contact with Bacon. A striking contrast was offered by John Donne, who represented a transition from the sixteenth to the seventeenth century, being in certain aspects the most medieval and in others the most modern writer of his time. In conclusion, Sir Walter showed how the turmoil of thought in Harvey's time is being repeated to-day. In both instances a phase of great and rapid expansion both in thought and wealth was followed by disillusionment on the intellectual side and greater stringency on the financial; old standards were destroyed before new ones could take their place and a new form of art and literature appeared.