The real worlds of Thoreau and Alcott and Emerson did at times so far overlap that they trod on common ground, but these periods were so brief and the spaces in common so small that soon they wandered apart, each circling by himself in an orbit of his own.
Words at best are poor instruments of thought; the more we use them the more ambiguous do they become; no man knows exactly what another means from what he says; every word is qualified by its context, but the context of every word is eternity.

How long shall we listen to find out what a speaker meant by his opening sentence ?--an hour, a day, a week, a month ?--these periods are all too short, for with every added thought the meaning of the first is changed for him as well as for us.
"Life" in common speech may mean either mere organic existence or a metaphysical assumption; we speak of the life of a tree, and the life of a man, and the life of a soul, of the life mortal and the life immortal.

Who can tell what we have in mind when we talk of life?
No one, for we cannot tell ourselves.

We speak of life one moment with a certain matter in mind, possibly the state of our garden; in the infinitesimal fraction of a second additional cells of our brain come into activity, additional areas are excited, and our ideas scale the walls of the garden and scatter over the face of the earth.

If we attempt to explain, the very process implies the generation of new ideas and the modification of old, so that long before the explanation of what we meant by the use of a given word is finished, the meaning has undergone a change, and we perceive that what we thought we meant by no means included all that lurked in the mind.
In every-day speech we are obliged to distinguish by elaborate circumlocution between a man's place of residence and that larger and truer life,--his sphere of sympathies.