The mind is a thing that dwells in diffusion, in succession; it can only concentrate on one thing at a time and when not concentrated runs from one thing to another very much at random. Therefore it has to concentrate on a single idea, a single subject of meditation, a single object of contemplation, a single object of will in order to possess or master it, and this it must do to at least the temporary exclusion of all others. <ref>http://incarnateword.in/cwsa/23/concentration#p7</ref>
powers of concentration ===
1. By concentration on anything whatsoever, we are able to know that thing.
2. By concentration, the whole will can be gathered up for the acquisition of any object whatsoever.
3. By concentration of our whole being on one status of itself, we can become whatever we choose. <ref>http://incarnateword.in/cwsa/23/concentration#p2 </ref>