By the time of Theodosius I (379-395), Christianity had become the state religion of the empire. With Christianity in power, ethical concerns broaden and included discussions of the proper role of the state. Render unto Caesar… is the beginning of a phrase attributed to Jesus in the synoptic gospels which reads in full, ""Render unto Caesar the things which are Caesar’s, and unto God the things that are God’s"". This phrase has become a widely quoted summary of the relationship between Christianity and secular authority. The gospels say that when Jesus gave his response, his interrogators "marvelled, and left him, and went their way." Time has not resolved an ambiguity in this phrase, and people continue to interpret this passage to support various positions that are poles apart. The traditional division, carefully determined, in Christian thought is the state and church have separate spheres of influence. Thomas Aquinas thoroughly discussed that "human law" is positive law which means that it is natural law applied by governments to societies. All human laws were to be judged by their conformity to the natural law. An unjust law was in a sense no law at all. At this point, the natural law was not only used to pass judgment on the moral worth of various laws, but also to determine what the law said in the first place. This could result in some tension. Late ecclesiastical writers followed in his footsteps. Christian democracy is a political ideology that seeks to apply Christian principles to public policy. It emerged in 19th-century Europe, largely under the influence of Catholic social teaching. In a number of countries, the democracy's Christian ethos has been diluted by secularisation. In practice, Christian democracy is often considered conservative on cultural, social and moral issues and progressive on fiscal and economic issues. In places, where their opponents have traditionally been secularist socialists and social democrats, Christian democratic parties are moderately conservative, whereas in other cultural and political environments they can lean to the left. Attitudes and beliefs about the roles and responsibilities of women in Christianity vary considerably today as they have throughout the last two millennia — evolving along with or counter to the societies in which Christians have lived. The Bible and Christianity historically have been interpreted as excluding women from church leadership and placing them in submissive roles in marriage. Male leadership has been assumed in the church and within marriage, society and government. Some contemporary writers describe the role of women in the life of the church as having been downplayed, overlooked, or denied throughout much of Christian history.