The most savage controversies are those about matters as to which there is no good evidence either way.

Summary

This quote suggests that the fiercest and most intense disagreemenets occur when there is a lack of substantial evidence supporting either side of an argument. In situations where there is little to no concrete information or proof available, people often hold steadfast to their beliefs or opinions and engage in heated conflicts. This may occur because without evidence to guide the discussion, personal biases and emotions tend to take precedence, resulting in vehement debates.