Philosophy makes a basic distinction between a subject and an object:
- A subject does things, it acts, and can make experiences. It is situated in relation to other subjects that exist outside itself.
- An object is a thing that is observed or experienced by a subject. As a subject may experience or observe other subjects, these are objects in the view of the observer.
The first modern philosopher to make this distinction was René Descartes. He made a distinction between mind and matter.