As a historian who studies missionaries, I am sometimes asked by my fellow Catholics: How did the Church think about evangelization in the past compared to the present? Typically it is clear that they regard one age as wiser than the other. The more progressively inclined assume that things are better today, whereas the traditionally minded look back to a lost golden age of missions and evangelization.
Questions like this cannot be answered straightforwardly, because we cannot really speak of the mind of the Church per se on this matter prior to the late nineteenth century. That was when Leo XIII began to employ the papacy in ways never quite seen before, issuing more wide-ranging encyclicals, letters, and exhortations than any of his predecessors.