6 ideas
Bergson separates two kinds of memory. Habit memory is a motor mechanism built up by repetition and stored in the body, like a lesson learned by heart, and it acts the past out without representing it. Pure memory records each moment once, as a dated and unrepeatable image, and it represents the past without acting.
The brain does not produce or store representations. It works like a telephone exchange that receives stimuli and delays, channels, or selects motor responses. Brain lesions therefore disrupt the mechanisms by which memories are actualized into action, not the memories themselves.
Conscious perception is what remains of the material world after a body filters out everything irrelevant to its possible actions. It is not a mental picture added on top of matter. What we perceive outlines our virtual action on things, so perception measures our power to act.
Memory is pictured as a cone whose broad base holds the whole of the past in pure memory. Its tip is the present point where the body meets the plane of action. Mental life moves between these levels: toward the tip it contracts memory into useful, action-ready forms, and toward the base it expands into dreamlike, detailed recollection.
Healthy mental functioning depends on attention to life, the body's ongoing adjustment of memory to present action. The dreamer drifts toward pure memory and loses practical grip. The purely impulsive person lives in habit and reflex with no past guiding them. Many mental disorders are reframed as breakdowns in this tension rather than losses of stored content.
Recognizing something familiar often requires no recalled image. It is the feeling of bodily movements smoothly ready to engage with it, as when a familiar street 'carries' us along. Attentive recognition is more complex: memory-images are projected outward to meet and fill in the perceived object, in a circuit between memory and perception.