Final answer:
Concepts can exist independently of humans or animals. They can exist in nature without human or animal perception. Philosophers like Plato and Kant believe in the independent existence of concepts.
Step-by-step explanation:
Concepts can exist independently of humans or animals. They are not limited to being products of the human mind. For example, concepts like redness or brightness can exist in nature without the need for human or animal perception. Philosophers like Plato and Kant believe that concepts exist independently in other worlds or as innate and necessary rules of thought. While concepts can be products of human experience, there are also concepts that are not easily reducible to simple meanings or ideas.