A concept is an abstract idea that serves as a foundation for principles, thoughts, and beliefs, examined across disciplines such as philosophy, psychology, and linguistics. Thinkers like Bertrand Russell viewed concepts as universals we perceive, while William James highlighted their function in organizing reality through mental frameworks.
Immanuel Kant differentiated a priori concepts as innate categories that shape experience, and Johann Friedrich Herbart associated concepts with repeated mental activities that influence character. These diverse perspectives illustrate how concepts connect abstract thinking with empirical reality, demonstrating their dual nature as both cognitive instruments and ontological elements.