The most savage controversies are those about matters as to which there is no good evidence either way. Persecution is used in theology, not in arithmetic, because in arithmetic there is knowledge, but in theology there is only opinion. p. 136.

Summary

This quote by Bertrand Russell highlights the intensity of disputes that revolve around subjects where there is a lack of substantial evidence to support either side. According to Russell, theological debates tend to be particularly heated and divisive because they rely on opinions rather than verifiable knowledge. In fields like mathematics, where evidence and facts are clear, persecution is unnecessary. Russell's quote implies that when there is uncertainty and no concrete evidence, conflicting beliefs can escalate into savage controversies.