Scottish common sense realism, also known as the Scottish school of common sense, is a realist school of philosophy that originated in the ideas of Scottish philosophers Thomas Reid, Adam Ferguson, James Beattie, and Dugald Stewart during the 18th-century Scottish Enlightenment. Reid emphasized man's innate ability to perceive common ideas and that this process is inherent in and interdependent with judgement. Common sense, therefore, is the foundation of philosophical inquiry. Though best remembered for its opposition to the pervasive philosophy of David Hume, Scottish common sense philosophy is influential and evident in the works of Thomas Jefferson and late 18th-century American politics.

Philosophical realism – usually not treated as a position of its own but as a stance towards other subject matters – is the view that a certain kind of thing has mind-independent existence, i.e. that it exists even in the absence of any mind perceiving it or that its existence is not just a mere appearance in the eye of the beholder. This includes a number of positions within epistemology and metaphysics which express that a given thing instead exists independently of knowledge, thought, or understanding. This can apply to items such as the physical world, the past and future, other minds, and the self, though may also apply less directly to things such as universals, mathematical truths, moral truths, and thought itself. However, realism may also include various positions which instead reject metaphysical treatments of reality entirely.