A Little History of Philosophy (Little Histories)

It's just that for Berkeley what we call a stone is nothing more than the sensations it gives rise to. There is no ‘real’ physical stone behind it causing the pain in the foot. In fact there is no reality at all beyond the ideas that we have.

Berkeley summed up this strange view in Latin as ‘Esse est percipi’ – to be (or exist) is to be perceived. So the fridge light can't be on, and the tree can't make a noise when there is no mind there to experience them. That might seem the obvious conclusion to draw from Berkeley's immaterialism. But Berkeley didn't think that objects were continua

Recognize that nothing matters. That way nothing will affect your state of mind, which will be one of inner tranquillity.

Life, he declared, is only worth living if you think about what you are doing. An unexamined existence is all right for cattle, but not for human beings.