"Men, it has been well said, think in herds; it will be seen that they go mad in herds, while they only recover their senses slowly, and one by one"

Charles Mackay’s statement offers a profound reflection on collective human behavior, particularly regarding societal trends, public opinion, and the psychology of crowds. He illustrates the tendency for people not only to gather physically in groups but to share beliefs, fears, hopes, and ideas collectively, sometimes to their detriment. When he observes that “men…think in herds,” he draws attention to the shared mindset that can overtake individuals within a group, causing them to adopt attitudes or convictions they may never have held alone. Herd mentality can manifest in events like financial manias, panics, political movements, or social fads, where rational individual judgment is subsumed by the emotional currents sweeping through the group.

Mackay further contends that this collective thinking can lead to widespread folly: people “go mad in herds,” swept by mass delusions or irrational passions to such an extent that their reasoning becomes clouded. The 'madness' he refers to isn’t necessarily clinical insanity but rather a temporary suspension of critical thought and sober judgment. As groups adopt increasingly extreme or unfounded ideas, momentum builds, peer pressure intensifies, and a feedback loop develops, making dissent difficult. Historical examples abound, from financial bubbles like the South Sea or Tulip Mania to political or social hysteria.

The final observation, “they only recover their senses slowly, and one by one”, underscores the contrasting pace of rationality’s return. While mass irrationality can ignite rapidly, a return to clarity is a more solitary and gradual process. The path back to sense requires personal reflection and the courage to question popular opinion, often without the support of the group. Reassessment and recovery tend to occur individually, as people each confront the consequences of collective error and slowly disentangle themselves from the delusions that had gripped the many. Mackay’s insight remains deeply relevant for understanding how societies can be swept up by groundless excitement or fear, and why wisdom often reemerges so hesitantly.