Definition:
Abstraction is the intellectual process through which the mind separates general qualities or universal characteristics from particular objects and experiences. Human beings encounter individual things in the world, yet through abstraction they form broad concepts that make knowledge and classification possible. Philosophers disagree about whether abstract entities exist independently in reality or merely in human thought.

Thinkers:

• Plato — universals exist independently as Forms.
• Aristotle — universals are abstracted from experience.
• John Locke — emphasized general ideas formed by abstraction.

Example:
After seeing many individual dogs, one forms the abstract concept “dog.”