For those who have set up a high spiritual ideal and moral character for themselves and who have acquired sufficient knowledge through study or lectures about the principles and fundamentals of yoga, there is an excellent exercise which will help them through the elementary phases of development; but to others who are highly neurotic, mentally disturbed, approaching or under psychosis, it is not only not recommended, but would be dangerous. This exercise is to concentrate all the attention upon one object in the surroundings and to keep it there. All associated ideas, analysis, and thoughts about the object should be thrown out. It is not a matter of reflecting about the object, but of holding it in the view and in the mind to the exclusion of everything else.
One can begin with very short periods of practice and go on slowly to longer ones, but when some amount of success has been established by the rigorous use of willpower the object should be chosen from some things elevating to the mind such as beautiful music or beautiful landscape. For the elementary phase, about fifteen minutes should be the maximum, but for this uplifting phase one may go on longer.
-- Notebooks Category 4: Elementary Meditation > Chapter 3 : Fundamentals > # 138
