Paracelsus

n what is now Switzerland, at some point in the year 1493, Philippus Aureolus Theophrastus Bombastus von Hohenheim was born. Later, he was known simply as Paracelsus and became the father of what would become the science of toxicology, or poisons. As a medical man, he was different from all those of his time. His most important finding was the concept of a threshold. That poisons, drugs and medicines had to be present in certain amounts before they did either harm or good, and it was necessary to know which substance was responsible. In modern times, we have the concept of the Minimum Effective Dose. Prior to Paracelsus the linkage between a medicine and the amount taken was an unknown concept. To us in the modern world, the idea seems so simple, but at the time, knowledge came from books and the more ancient and venerated the book, the better.

Paracelsus wrote:

“What is there that is not poison? All things are poison and nothing is without poison. Solely the dose determines that a thing is not poison.”

By specifying that a low dose will present no ill effect, Paracelsus helped define the difference between hazard (the potential for harm) and risk (the chance of that harm occurring). Paracelsus was also an incessant critic of all the medical writings that came before him. It was his belief that only by observation could the effectiveness of a treatment be determined.

Paracelsus wrote:

“My accusers complain that I have not entered the temple of knowledge through the right door. But which one is the truly legitimate door—Galen and Avicenna, or Nature? I have entered through the door of Nature. Her light, not the lamp of an apothecary’s shop, has illuminated my way.”

He was also not impressed by his colleagues.

“The best of our popular physicians are the ones that do the least harm. But, unfortunately, some poison their patients with mercury; others purge them or bleed them to death. There are some who have learned so much that their learning has driven out all their common sense, and there are others who care a great deal more for their own profit than for the health of their patients.”

It was not until centuries later that his emphasis on observation was considered valuable, and his greatness appreciated. He was the first of a new breed: the natural philosopher, later to become the scientist, one who believes that knowledge is gained through meticulous observation and analysis.

Today, observing what one sees seems obvious, but I would hazard a guess that extraordinary blindness, fixed ideas and the insistence they are true in spite of contrary evidence, have not disappeared altogether into the mists of the past. It takes incredible strength and courage to swim against the currents of what society believes to be true in any age. There is no greater test, no graver peril, and no bigger challenge—and yet, so much to be gained.