Someone asked how the Four Foundations of Mindfulness -- body, feeling, mind, and phenomena -- relate to the Five Aggregates -- form, feeling, perception, mental formations, and consciousness. Is body the same as form? Is feeling the same? How is mind related to mental formations?

The Basic Relationship

At a basic level, body and form are the same thing, and feeling is the same as feeling. Consciousness sits at the center of the aggregate of mental formations. Phenomena relate to consciousness carrying the mind into experience -- consciousness is like a vessel the mind relies on, carrying it into form, taste, smell, and sound. When it arrives there, feelings and moods arise, which are also a kind of phenomena, though the word "phenomena" has a broader meaning.

Mind and mental factors can be called mental formations, because they are what shapes thought and feeling as they arise. Part of this belongs to phenomena; another part belongs to consciousness, which carries the mind to contact forms, tastes, smells, sounds, and the moods that arise from them.

Why Different Terms Are Used

Because the human body also has subtler bodies layered within it. Feeling likewise has the feeling of the human body, and a subtler feeling layered upon it. The mind of the human body sits at the center of its aggregate of mental formations. When any force takes hold, it overlays its own mind and mental factors onto the human mind -- hence the phrase "mind within mind," "feeling within feeling," describing this layering. The thought that arises as an inner voice relates to mind, while the feeling relates to mental factors, which in turn relate to phenomena -- wholesome, unwholesome, or neutral, depending on which force has taken hold. This is why different terminology from "form, feeling, perception, formations, consciousness" is needed, to avoid confusion.

The Five Aggregates Are Like a Computer

Form is like the casing that houses feeling, perception, mental formations, and consciousness -- the mental side. These four are layered in four levels. The first layer is feeling, which registers whether the force that has taken hold feels like happiness, suffering, or neither. It's like turning on a phone or computer -- the first thing displayed is which operating system is running. This is why feeling, as described across the scriptures, has only three types: happiness, suffering, and neither happiness nor suffering -- unlike the countless sensations consciousness picks up externally, like sour, sweet, salty tastes, or cool, hot, soft, hard touches.

Perception is like a hard drive storing data. Mental formations are like a CPU processing and shaping thought and feeling. Consciousness is the connector to the outside world, like a microphone or camera linking to the eye, ear, nose, tongue, and body. The Five Aggregates are thus like a robot controlled by the three natural forces, whichever manages to seize control in each moment -- and this all unfolds according to the law of karma.

The Four Foundations of Mindfulness -- Observing How the Forces That Possess Us Work

The Buddha taught us to be mindfully aware of body, feeling, mind, and phenomena, because when the three natural forces control a person, they act through exactly these four. They overlay their own body, feeling, mind, and phenomena onto the human being's. When wholesomeness overlays, the quality is higher -- like a "mentor" guiding what is correct and good, drawing on subtler bodies -- the refined human body, the celestial body, the Brahma body -- as fits the situation. The subtler the body layered in, the more easily and deeply Dhamma is understood. This is why some people grasp a teaching instantly, or reach deep states the very first time they meditate: a skilled Brahma body, experienced in refining the inner elements, is overlaid to help.

Conversely, when unwholesomeness takes hold as master of the house, it overlays the consciousness of realms lower than human -- hell beings, hungry ghosts, demons, animals -- causing behavior to become distorted: harsh speech, backbiting, idle chatter, and a descent through greed, aversion, delusion, lust, and the hindrances, all to keep drawing unwholesome energy in through that consciousness.