Two of the longest-standing debates in ethics have direct relevance to impact investing. The first is the debate over the relative value of outcomes and purpose. Is the priority achieving the most good, or is it acting according to a good purpose?

Both approaches have a long heritage in Western philosophy, and both also accord with common feelings about morality. Most people would agree, for example, that it would be better to give money to a charity that has clear evidence of its effectiveness than a charity that doesn’t, as the outcome of our giving matters as well as the act itself. But most would also agree that there is something more worthwhile about making someone better off through a conscious donation as opposed to that person finding some money we accidentally lost in the street.

Impact investing currently tries to straddle the importance of outcomes and purpose. Two of the main mantras for impact investors are “outcome measurement” and “intentionality.” We say it is very important to measure and prove outcomes; we also say the investor and investee should intend to achieve good things. But in practice these desires pull in different directions.

All impact investment organizations make judgements all the time—whether something counts as impact, how to think about measurement, and so on. Many of these questions are not technical.

Tensions arise and judgements feel tricky precisely because tools and systems do not get to the heart of the problem; these points ultimately connect to ethics and values. We should acknowledge that, be honest with each other when values come into play, and consider why that makes some discussions challenging.

We can use the tools that philosophers have honed over the centuries to help us reach clarity and make the right decisions—whatever “right” might mean.

Read the full article about the ethics of impact investing by Stephen Muers at Stanford Social Innovation Review.