The degree of one’s emotions varies inversely with one’s knowledge of the facts.

Russell’s aphorism claims an inverse relationship between emotional intensity and factual understanding: the less one knows about a situation, the more one is likely to react with strong feeling (fear, outrage, enthusiasm), while fuller knowledge tends to moderate and complicate response. The point is not that emotion is always irrational, but that ignorance encourages simplified narratives and overconfidence, which can amplify passion. Read in a Russellian key, it also gestures toward an ethical ideal of intellectual discipline—seeking evidence, distinguishing what is known from what is assumed, and resisting the emotional rewards of certainty. It remains a pointed warning about propaganda and public opinion, where partial information can be used to inflame sentiment.