While public support is vital, movements don't just happen. They require specific individuals who act as catalysts. The British abolitionist movement, for example, is inseparable from Thomas Clarkson, who was the first person to envision a national public campaign and dedicate his life to it, turning a latent issue into a powerful political force.

Quaker activists opportunistically leveraged the political language of the American Revolution. As colonists argued for their 'natural rights' against British rule, abolitionists like Anthony Benezet co-opted this discourse, pointing out the hypocrisy and applying the same logic to the rights of enslaved people, forcing the issue into the public sphere.

Anti-slavery movements thrived in 'societies with slaves,' like Pennsylvania, rather than 'slave societies,' like Barbados. In Pennsylvania, slavery existed, so people were confronted with its morality, but the economy wasn't dependent on it. This allowed for questioning without risking the collapse of the entire socio-economic order.

The fact that slavery abolition was a highly contingent event demonstrates that moral progress isn't automatic. This shouldn't be seen as depressing, but empowering. It proves that positive change is the direct result of deliberate human choices and collective action, not a passive trend. The world improves only because people actively work to make it better.

The first organized anti-slavery movement among the Quakers was initially focused inward. They used opposition to slavery as a way to define their collective religious identity and reinforce their values of pacifism and simplicity, not as a campaign to change broader society.

There's a vast distance between knowing something is wrong and acting on it. Like modern people walking past the homeless or eating meat despite ethical concerns, societies for centuries possessed the moral insight that slavery was wrong but did nothing. Successful movements are the rare exception, not the norm.

The successful anti-slavery movement in Britain was founded primarily by entrepreneurs who applied their skills in scaling companies and operations to a moral cause. This historical example shows that business acumen is a powerful, and perhaps essential, tool for large-scale social change.

During the American Revolution, Britain and the colonies used slavery to attack each other's character. Each side accused the other of hypocrisy without any genuine commitment to abolition. This political mud-slinging was crucial because it transformed slavery from a normal fact of life into a blameworthy, immoral act in the public consciousness.

Germ theory was resisted by the medical establishment and adopted last by doctors. The shift was driven by outside cultural forces, like the 'Rainy Day Club,' that created social proof and new public expectations. This shows that profound change is often forced upon institutions from the outside in.