An idea is a concept or mental impression. Very often, ideas are construed as representational images; i.e. images of some object. In other contexts, ideas are taken to be concepts, although abstract concepts do not necessarily appear as images. Many philosophers consider ideas to be a fundamental ontological category of being. The capacity to create and understand the meaning of ideas is considered to be an essential and defining feature of human beings. In a popular sense, an idea arises in a reflex, spontaneous manner, even without thinking or serious reflection, for example, when we talk about the idea of a person or a place.
One view on the nature of ideas is that there exist some ideas (called innate ideas) which are so general and abstract, that they could not have arisen as a representation of any object of our perception, but rather were, in some sense, always in the mind before we could learn them. These are distinguished from adventitious ideas which are images or concepts…