The mind generally takes up various objects, runs into all sorts of things. That is the lower state. There is a higher state of the mind, when it takes up one object and excludes all others.
In the matter of physics, the first lessons should contain nothing but what is experimental and interesting to see. A pretty experiment is in itself often more valuable than twenty formulae extracted from our minds.
To understand the totality of this extraordinary thing called life, one must obviously not be too definite about these things. One cannot be definite with something which is so immense, which is not measurable by words. We cannot understand the immeasurable so long as we approach it through time.
The senses collect the surface facts of matter... It was sensation; when memory came, it was experience; when mind acted, it was knowledge; when mind acted on it as knowledge, it was thought.