Bishop Berkeley, the buoyant, Irish, Enlightenment philosopher was an Idealist positing all that existed was mind and its ideas: matter – substance – he found to be an object of perception. Of course, the thousands of words that clarify and expound this theory you’ll have to wander off to find for yourselves.
It springs to mind in virtue of AL Kennedy’s broadcast on Mindfulness. This concept means paying attention in a particular way: on purpose, in the present moment, non-judgementally to increases awareness, clarity and acceptance of the Now.
This is part of what we mean by Listening; naturally we’re delighted acceptance of this branch of thinking has so thoughtful an audience.