His conservativism made him oppose major changes to the marriage laws.

conservativism 是由形容词 conservative（保守的）加上名词后缀 -ism 构成的名词，表示"保守主义"这种思想或立场。conservative 来自动词 conserve（保存、保护），指倾向于保持传统或现有状态的倾向。