
This phrase is so common in the world of fitness and sports, when one is asked to establish the mind body connection to activate muscles or to fire the brain into activating some muscles in a specific exercise. Anyone who works out is familiar to this idea. However, the mind body connection or relationship is not new in philosophy; it is actually a very old dilemma that is found also in religions. Therefore what is the mind and what is the body? Is the mind inside the body or vice-versa? Are we made of both or are these two the same dimension? In this dialectic dissertation, two potential answers are found: dualism and monism. For the depth and complexity of this subject, the study will be developed through multiple posts.
Definitions and etymologies:
Before digging into dualism and monism, the everlasting starting point of any analysis must take into consideration etymologies and definitions of the two main concepts, the mind and the body, as in the spirit and the matter, to give a frame to our study. Here are the conceptual ramifications of each one:
Spirit → mind →consciousness
Matter → body → brain
At a first glance, these concepts appear to belong to different categories which will be shown later on in the common definitions. But, scientifically speaking and in certain philosophical schools, they are not as different as they may sound. We will start with matter then with spirit.
Matter:

Matter is a physical substance in general, as distinct from mind and spirit; (in physics) that which occupies space and possesses rest mass, especially as distinct from energy. Albert Einstein proposed a definition of the matter that was, and maybe still, confusing to the non-specialists: matter is energy, better known in his formula E=mc2 where E is energy, m is mass, and c is the speed of light. This new definition of the matter transformed the latter into a non-perceptible phenomenon. Put is simply, matter is for the common people what is tangible or perceptible with a form, dimensions and content. For physics since the 20th century, it is energy for Einstein and a complete uncertainty of movements in quantum physics. In both definitions, there is no mention of the spirit.
To make things more complicated, some ancient and current tribes believe that matter is animated by a spirit; a belief better known as animism.
So, as one can see, the problematic concept is spirit.
Body:
The body is made of matter, of physical interacting substances that can form an organism or a structure of organs. In a living body, organs are made of tissues and cells where each cell is subdivided and has a certain function. That’s why the body functions as a whole.
Spirit:
The spirit has many definitions but to this study, the main one will be retained. The spirit is the non-physical part of a person which is the seat of emotions and character, known as the soul.

Spirit comes also from the Latin word anima, which is the principle of animation. As aforementioned, some people believe that nature is animated, that means has a spirit as spiritus, breath (the word animal comes from anima). Aristotle believed that animals had a spirit. Of course, later on spirit as a concept will have a different meaning.
Mind:
The mind is the invisible and non-perceptible element of a person that enables them to be aware of the world and their experiences, to think, and to feel; the faculty of consciousness and thought. The correlation between mind and thought can be seen in the origin of the word:

Old English gemynd ‘memory, thought’, of Germanic origin, from an Indo-European root meaning ‘revolve in the mind, think’, shared by Sanskrit manas and Latin mens ‘mind’.
Therefore the concepts of mind and consciousness are synonyms.
After a long platonic influence and a long religious tradition, precisely monotheistic religions, only humans have a spirit and a mind; the rest of creatures are only determined by their instincts. The questions remain the same: what is the mind and what is the body? Is the mind inside the body or vice-versa? Are we made of both or are these two the same dimension? In this short dialectic dissertation, two potential answers are found: dualism and monism on more upcoming posts.