Philosophy
Merleau-Ponty treats perception as an embodied engagement with the world rather than an internal copy of external objects.
A person's projects charge their surroundings with meaning, so countless cues spring up to guide action, like signs leading a museum visitor. When that capacity is damaged, the world goes flat and fixed, and one's own body becomes an object to steer clumsily rather than an extension of oneself.
One cannot understand ordinary functioning by simply adding back whatever a patient lacks. A loss changes the whole way the world is organized for that person. So a case of impairment must be read as a different overall pattern, not a subtraction.
Perceiving is not passively registering inner states triggered by stimuli; it is an active reaching toward something other than oneself. There is no 'pure sensation' to start from. Consciousness is always consciousness of a world it is already engaged with.
The body is not just a physical object we happen to carry; it is what arranges our situation and lets a world appear at all. It sits in the middle, at once a thing among things and the one who experiences. That double status is meant to dissolve the split between mind and matter.
We do not build experience out of separate sensory atoms; each element means something only through its place in a larger pattern. A circle is grasped first by its look, its 'face,' not by its mathematical rule. The whole exceeds the sum of what composes it.
Detached judgment and analysis are not the ground floor of knowing. They work on a perceptual field that already has structure, trying to spell out what was given. So lived experience is basic, and scientific or abstract accounts are derived from it.
You cannot describe a thing apart from the someone it shows up for, and the self only shows itself through the things it is busy with. Each is a pole of one continuous field. Neither can be taken first and the other built from it.
Choice is always shaped by one's body and circumstances. On this view, freedom comes from engaging with that lived situation, not from rising above it.