"How do you know?

Since forever, this has been one of the hardest questions to answer. And until the scientific revolution, unless you had firsthand knowledge (“I tried meditation and it did this for me, but I can’t say what it will do for you”), you had to rely on others you trusted (“The One-Who-Knows-All says that this plant will cure your anxiety”). With the advent of scientific experimentation, the standard for knowledge began to shift, and nowadays with other kinds of authority in decline, the gold standard for knowledge is whether it has been tested in an experimental setting."

Barry's identification of the gold standard for knowledge might be a little misleading. From my perspective this implies institutional organizations and 'scientific studies' are required to give us confidence. I would suggest that experimentation is important but for mindfulness and other types of spiritual development the experiment and experimenter are one and the same. No institution need apply. You "know" from repeated results of your own exploration. This is "Subjective Science". Objective science is the science of objects - things.

The Science of Mindfulness: A Healthy, Growing Baby — by Editor-in-Chief Barry Boyce