Indeed. This is an excellent explanation of exactly how fundamentalism works: everything must reduce and cohere down to a particular set of principles, rather than reacting and adapting to reality with an understanding that the present understanding of morality isn't fixed and is subject to change.

Once you pick a line in the sand you will not budge over, you have maimed your capacity for reason. So yes, the only principle I could ever hold is an impossible one. Fortunately, I do not hold it.