It is argued that the sensorium of God was introduced into the Quaestiones added to the end of Newton’s Optice (1706) as a way of answering objections that Newton had failed to provide a causal account of gravity in the Principia. The discussion of God’s sensorium indicated that gravity must be caused by God’s will. Newton did not leave it there, however, but went on to show how God’s will created active principles as secondary causes of gravity. There was nothing unusual in assuming that God, acting as the First Cause, operated in nature by means of secondary causes; but it was unusual to devote as much time to discussing God’s precise role as to discussing the secondary causes themselves. It is contended that Newton felt the need to do this to persuade readers that what might seem like a second cause that could not possibly work could be made to work by the omnipotent God.

This article examines the medical and political discussions regarding a controversial medicinal bark from Ecuador – cundurango – that was actively sponsored by the Ecuadorian government as a new botanical cure for cancer in the late nineteenth century United States and elsewhere. The article focuses on the commercial and diplomatic interests behind the public discussion and advertising techniques of this drug. It argues that diverse elements – including the struggle for positioning scientific societies and the disapproval of the capacities of Ecuadorian doctors, US abolitionist history, regional and local political struggles – played a role in the quackery accusations against cundurango and its promoters. The development and international trade of this remedy offer interesting insights into the global history of drugs, particularly how medical knowledge was challenged during a period when scientific medicine was struggling for hegemony. It explores how newspapers expanded “the public interest” in a possible cancer cure.

Eusapia Palladino (1854-1918) is remembered as one of the most famous mediums in the history of spiritualism. Renowned scientists attended her séances in Europe and in the United States. They often had to admit to being unable to understand the origin of the phenomena produced. Cesare Lombroso, for example, after meeting Eusapia, was converted first to mediumism, then spiritualism. This article will retrace the early stages of her career as a medium and shed light on the way she managed to gain the attention of scientists. It will also show why they chose her as an epistemic object.

In the early twentieth century, counting and speaking horses, like the famous Clever Hans or the “Horses of Elberfeld,” became widely debated subjects in experimental psychology. The idea was to determine whether their learning success was only a fraud, or if it might open up a new chapter in “animal psychology” - or even belong to the realm of parapsychology and telepathy. When their tricks were discovered, the teachers of the animals were marked as charlatans. Both the attempts to detect charlatans and the efforts to avoid this accusation during the talking horse experiments proceeded using the method of introducing new levels of communication into the human-animal interaction process in order to substantiate each respective standpoint. This paper argues that the scientific studies and debates on the talking horses are relevant not only from psychological, biological, and semiotic vantage points, but also from the perspective of communications theory, giving rise to the foundational issue of levels of communication.

The world of charlatans is a world of constantly shifting borders and redefinitions, a world of crossed lines and pushed boundaries. Can one even speak of “the world” of charlatans in the singular, when the examples we are given to read in this volume reveal such great diversity that they seem to defeat any attempt to define common traits, as Roy Porter (1989) tried to do in his time? Certainly, commercial interests and the lure of a quick and easy profit seem to have motivated some charlatans. Certainly, the universal effects of the nostrum or (psycho)therapeutic procedures were often put forward as a commercial argument. Certainly, many had an itinerant career; but this was not always the case. In fact, these traits are not shared, and the main reason is probably that, aside from a very particular context in early modern Italy, the qualification of charlatan was not claimed by the actors themselves, but was attributed to them by others, be they contemporaries or later historians. These features are therefore only common if we understand them as stigmata1 attributed to charlatans by those who wish to distinguish themselves from them or to draw a line between orthodoxy and heterodoxy.