The sun is seen to pour down and expend itself in all directions, yet is never exhausted. For this downpouring is but a self-extension; sunbeams, in fact, derive their very name from a word signifying ‘to be extended’.
To understand the property of a sunbeam, watch the light as it streams into a darkened room through a narrow chink. It prolongs itself forward in a straight line, until it is held up by encountering some solid body which blocks its passage to the air beyond; and then it remains at rest there, without slipping off or falling away.
The emission, and the diffusion, of thought should be the counterpart of this: not exhausting, but simply extending itself; not dashing violently or furiously against the obstacles it encounters, nor yet falling away in despair; but holding its ground and lighting up that upon which it rests. Failure to transmit it is mere self-deprivation of light.