The terms Old Lights and New Lights (among others) are used in Protestant Christian circles to distinguish between two groups who were initially the same, but have come to a disagreement. These terms originated in the early 18th century from a split in theological approach among Calvinist denominations concerning the nature of conversion and salvation. Since then, they have been applied in a wide variety of ways, and the meaning must be determined from each context. Typically, if a denomination is changing, and some refuse to change, and the denomination splits, those who did not change are referred to as the "Old Lights" and the ones who changed are referred to as the "New Lights".