You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Presbyterianism

Context:
The Westminster Confession is "The principal subordinate standard of the Church of Scotland" but "with due regard to liberty of opinion in points which do not enter into the substance of the Faith" (V). This formulation represents many years of struggle over the extent to which the confession reflects the Word of God and the struggle of conscience of those who came to believe it did not fully do so (e.g. William Robertson Smith). Some Presbyterian Churches, such as the Free Church of Scotland, have no such "conscience clause".

Question:
Who was one person who did not fully believe the struggle of conscience?

William Robertson Smith