Since returning from this year’s Council on Foundations conference, I have been thinking a lot about systems change: where it’s happened, how it happens, and what philanthropy can do to catalyse change. Can the pattern of changing social norms be learned and repeated? In my experience, large-scale social change requires pulling at least two out of three massive levers: government, the private sector, and civil society.

The kind of social change that improves quality of life for large numbers of people, I’d argue, happens when civil society works alongside public and private actors.

Let’s take the example of cigarette smoking. If not for the American Cancer Society and their volunteers, public actors like the Centers for Disease Control might not have acted to curb smoking. We experienced a social movement building across the country more than 40 years ago, and saw a deeply committed group of people including well-resourced people putting their time, energy, and money into media and lobbying government to reduce smoking and its health hazards. But these things take time to mature and coalesce. A movement requires sustained attention, financial resources, and work across political and social divides. With deep efforts of philanthropies like the Bloomberg and Gates Foundations, among others, and a concerted effort by legislators and public health groups, U.S. rates of smoking have reached a historic low.

Can philanthropy and foundations accelerate a tipping point? Each issue area is different but we can play a role in two ways: launching platforms that bring change agents together and creating the connective tissue that makes two plus two equal five. These can make for a powerful accelerator. Can we convene civil society, government, and the private sector in ways that uncover an unexpected alignment of interests?

We’re starting to see that around climate change with mayors, governors, venture capital groups, and citizens’ groups in the U.S., each advocating their own interests and coming together. If not for the early work of the Rockefeller Foundation and their Bellagio Platform, what we now call ‘impact investing’ would not have happened in the way we know it today.

But we must have eyes open to the obstacles. There are also well-resourced actors who stand to lose by changing the status quo. They are often closely aligned with powerful interests in government, the private sector, and even civil society. The movement to stop gun violence has faced exactly these challenges for decades. The global movement to mitigate climate change is facing resistance from very powerful actors.

Still, the anti-smoking movement also faced one of America’s most powerful industries. The American Cancer Society would not have reached their goal without the deep and sustained support of philanthropy working alongside civil society. Often the convening of villages, cities, companies, and governments is what creates a movement that cannot be stopped. As Margaret Meade reminded us, ‘Never doubt that a small group of thoughtful, committed citizens can change the world; indeed, it’s the only thing that ever has.’ As foundations and philanthropists, we have an important role to play in this—with a duty to live up to our highest values and deploy our resources for positive social change.

Aleem Walji is CEO of Aga Khan Foundation USA