He uses a negative definition so that the mind cannot make it into something to believe in war into a superhuman accomplishment, of goal that is impossible for you to attain.
Power of Now
It is the first book i read on Mindfullness which brings the world to a still and brings along a deep sense of peace within. Appreciating beauty , watchine nature mindfully, being in the present are a few highlights of what this book has got to offer. This is an awesome piece of Sacred test to brind along a deep inner transformation