Reformism is the belief that gradual changes through and within existing institutions can ultimately change a society's fundamental economic system and political structures. This hypothesis of social change grew out of opposition to revolutionary socialism, which contends that some form of revolution is necessary for fundamental structural changes to occur.

Reformism is the belief that gradual changes through and within existing institutions can ultimately change a society's fundamental economic system and political structures. This hypothesis of social change grew out of opposition to revolutionary socialism, which contends that some form of revolution is necessary for fundamental structural changes to occur.