《论衡·卷二十六·知实篇》
大凡论述事理的人，如果违背了事实而不举出证据，那么，即使道理讲得再动听，说得再多，大家也还是不相信的。
凡论事者，违实不引效验，则虽甘义繁说，众不见信。
Generally speaking, when someone discusses the theory of things but goes against the facts and doesn't provide evidence, even if the theory sounds good or is said many times, people won't believe it.