5. Association of images and ideas
1. Sensation, perception, image and idea
We distinguish the sensation from the perception. By the sensation, we realize a quality such as color, taste, smell, etc. By the perception, we realize the full object such as a table, a pen, a computer, etc.
We also distinguish the perception from the image and idea. Perception is the knowledge of an object which is absent. For example, I have the perception of the table and the pen that are in front of me, while I have the image of a car and a helicopter that I saw a few days ago.
Perceptions and images with specific knowledge are acquired by the senses, but we also have abstract knowledge acquired with our understanding, thinking and reasoning. Abstract knowledge are called ideas or concepts.