The brain in the gut – ***the second brain*** – plays a major role in human happiness and misery—but few people know it exists. Dr. Michael Gershon, co-founder of the neurogastroenterology field, explains why on both counts.

“We all experience situations in which our brains cause our bowels to go into overdrive. But in fact, messages departing the gut outnumber the opposing traffic on the order of about nine to one.” Michael D. Gershon, M.D.

Introduction

Published in 1998, The Second Brain by Michael Gershon addresses an important and neglected subject within the field biology, and which carries especial significance to medical theory and practice. This subject is the Enteric Nervous System (ENS) – the nervous system of the bowel – and the complex role that it plays in the body. In fact, the ENS displays a complexity of functioning akin to that of the brain—hence “the second brain”.
Throughout the book, Gershon also reveals how the second (or “lower”) brain has been overshadowed by the first (or “higher”) brain within the science and medical professions, in matters of theory, research, and medical treatment; and his book represents a most substantial effort to redress the balance. Most significantly, Gershon highlights the fact that gut problems are routinely blamed on the brain; that is, on neuroticism of one kind or another—when it has for long been scientifically established that the gut itself – which is, “with respect to intestinal difficulties, right at ground zero” – perfectly capable of causing “enteric havoc” independently of the brain. Indeed, the independent functioning of the gut is stressed throughout this work, illustrated by references to scientific experiments and biological knowledge.
Although Gershon – who was part-founder of the new medical field called neurogastroenterology – has effectively raised the scientific and medical profile of the enteric nervous system from underserved obscurity, his work still remains both highly relevant and insightful today with regards to the personal and medical implications of a malfunctioning gut.

For the proper philosophical discussion about any particular thing, the identification of the thing itself is more important than the word used to refer to it: A word is merely a tool used to approximate the meaning of a concept, thus enabling an expedient means to refer to that concept in conversation or writing. In a way, this conventional approximation of conceptual meaning highlights the purpose of Philosophy, which I define here as the unmotivated, uncompromised expression of the innate need to Understand. And, Understanding is perhaps the most important concept to philosophise about—which I define here as the pure and thorough attempt to clarify the essence and significance of a thing. Thus for this essay, a cluster of related ‘things’ I consider worthy of discussion are most closely approximated by the word ‘understanding’, with each of these things representing a particular aspect of that concept, thereby being a different sense of its meaning. Hence, I will use the word ‘understanding’ in multiple senses, supported by my definition of each one; and by which I attempt to describe these particular aspects of Mind and Life.