‘My thesis shows how all of Joseph Glanvill’s works on philosophy, pastoral care and belief fit together. Joseph Glanvill was an early fellow of the Royal Society of London and an early philosopher of science. He was also a respected clergyman and preacher. He was actively writing between 1660 and 1680.

Glanvill’s primary motivation was to improve our knowledge of the natural world by establishing a science of witchcraft and proving that spirits, demons and witches were real. Using Glanvill as a case study, I demonstrate how society shifted from a supernatural understanding of the world to scientific perspective.

Glanvill attempted to undertake scientific-level investigations into supernatural phenomena. Like many others, Glanvill believed that there was a conspiracy of witches in league with Satan trying to bring about the end of civilisation.

His main work on witchcraft, the Saducismus Triumphatus, explains what witchcraft is, what witches do and why we shouldn’t let them do it. It questions how it all works, and makes suggestions that could be studied further. One of his main objectives was to find one undeniable case that proved witchcraft existed.

I think Glanvill helped change popular beliefs about diabolical witchcraft because he made an evaluation of the supernatural. The rise of science changed the way that the majority of people interpreted the world, and the way they believed the world worked.

Glanvill himself was very interested in epistemology, how knowledge is formed, and cosmology, the understanding of the universe.

He was writing in a period of turbulent intellectual change. The Church was still so influential in society and many people accused The Royal Society of being atheist because of its interest in science and the natural world.

Glanvill helped to refute this and protect them from those sorts of accusations. If those accusations had been left unchecked, there is a possibility that science may never have gotten off the ground.

At this time, supernatural entities, angels, demons, fairies were thought to be just another part of the natural world. Across Europe and into New England, many people had always had some form of belief in spiritual beings.

[Glanvill] was writing in a period of turbulent intellectual change. The Church was still so influential in society and many people accused The Royal Society of being atheist because of its interest in science and the natural world.

Creatures like fairies were as real to them as cows and sheep, only harder to see or catch. This is why Glanvill thought he would be able to study them using scientific methods.

One contention Glanvill developed was the poisonous vapours hypothesis, which was based on the notion that spiritual beings are actually corporeal – that they have an aerial body.

In the British context, belief that witches had familiar spirits was common. The “familiar” had a number of possible roles. They might tell the witch information or the spirit might be sent out to do damage on the witch’s behalf.

In return, the witch was expected to feed the familiar. This demonstration of allegiance to the Devil often involved the witch allowing the familiar to drink their blood.

People arguing against the existence of witchcraft claimed that the belief in witchcraft was the effect of a substance in the body called melancholy. Melancholy caused depression, delusions and many things that we could consider mental illness today. Glanvill’s poisonous vapours hypothesis took this, one of the main arguments against witchcraft, and turned it. Glanvill combined this idea with the beliefs about familiars. He suggested that when a witch feeds her familiar, the spirit sends a poisonous vapour into her body.

The melancholy acts as the medium through which this poisonous vapour allows the familiar spirit to influence the witch.

For Glanvill, scientific training helped you become a better Christian. It helped you have more faith and strong faith helped you fight excessive melancholy.

Glanvill’s pastoral care ties in again with this poisonous vapours hypothesis. Many of his “theological works” were more about how to help people in his congregation. An abundance of melancholy was central to how witchcraft works for Glanvill. How you prevented the build-up of melancholy was through faith.

For Glanvill, scientific training helped you become a better Christian. It helped you have more faith and strong faith helped you fight excessive melancholy. He identified the Royal Society’s scientific method as the right kind of training for this purpose.

Ultimately, Glanvill’s belief that there could be a science of the supernatural continued to promote the belief in diabolical witchcraft for a period, but that was part of a process. In the end, more and more of these phenomena were explained by other areas of science rather than demonology or a science of the supernatural.

Glanvill’s ultimate failure to produce demonstrable scientific theories of diabolical witchcraft weakened the position of people arguing for the existence of witchcraft.

My research showed that this was one of the most important things that helped fuel this societal shift from a predominantly supernatural to predominantly scientific approach to the world.’

► Julie Davies’ thesis is titled: “Science in an enchanted world: Philosophy and witchcraft in the work of Joseph Glanvill.”

* My PhD is an irregular series in which The Citizen speaks with recent Melbourne University PhD graduates.