Nominalism

Nominalism is a belief in philosophy that says things like "universals" and "abstract objects" do not exist in reality. Instead, they are just names or labels we use. For example, concepts like "strength" or "humanity" are not real things on their own but are simply words we use to describe many individual things that share similar characteristics.^[1][2]

There are two forms of nominalism. One denies the existence of universals, which are qualities or properties that can appear in different things, such as the idea of "redness" in red things. The other denies the existence of abstract things, which are things that are not tied to a specific time or place, like numbers.^[3]

Most nominalists believe that only physical things that exist in time and space are real, while universals are just ideas we have after seeing individual things.^[4] Some, however, believe that certain abstract entities, like numbers, are also real but different from physical objects like chairs or animals.

Nominalism deals with the problem of universals, a question about which things like "catness" or "greenness" really exist outside our minds. Nominalism opposes realism, an idea that universals do exist freely of the things we see in the world. This debate has been said throughout history, dating back to philosophers like Plato and Aristotle, who had different views on this issue.

In the middle ages, philosophers like Roscellinus and William of Ockham were famous in developing nominalism. Ockham's version of nominalism, known as conceptualism, argued that universals exist only as ideas in our minds, not as real things in the world.

Nominalism has also affected modern philosophy, with people like Thomas Hobbes^[5] and Rudolf Carnap^[6] supporting it. In mathematics, nominalism suggests we should do math without assuming that abstract sets or groups exist as real entities.

Nominalism is a way of thinking that sides with simplicity, to explain the world without adding theories or things that aren't necessary. Some philosophers argue that nominalism helped turn modern thinking and continues to affect modern philosophy and science.