Ideas is the word most frequently used to include all the operations and states of mind.
Our ideas are often referred to as divided into two classes, viz., ideas gained by the senses, and ideas that pass through the mind without the aid of the senses.
Intellectual Powers.
The power to gain ideas by the five senses is called sensation or perception.
The power to have ideas without the use of the senses is called conception.
Per is the Latin word for by, and con is the word for without. So we have perceptions by the senses, and conceptions without the senses.
Imagination or fancy, is the power to make new combinations of our conceptions.
Memory is the power of recalling past ideas, and of recognizing them as having existed before.
Judgment is the power of comparing ideas, and noticing their relations to each other.
Abstraction is the power of noticing certain parts or certain qualities of things, while other parts or qualities are unnoticed.