The very nature of the evolutionary work to be done by reincarnation necessitates a sacrifice of memory. One useful purpose of the confinement of consciousness in matter, through the use of a physical body, is that it narrows the scope of consciousness and thereby increases its efficiency. The consciousness of the ego sweeps over a vast range, forward and backward, including all past incarnations. But the limitation of matter which compels consciousness to be expressed through a physical body, focuses the attention on the evolutionary work immediately in hand. The brain becomes the instrument of consciousness but also, fortunately, the limitation of consciousness. If there were not loss of memory our minds would now range over the adventures of thousands of years in the past. It would encompass a vast drama with countless loves and hates, of many lives filled with pathos and tragedy. To thus distract the mind from the present life would retard our progress. When one is alone and in a secluded place one can think better and accomplish more than when in the midst of turbulent scenes and throngs of people. When there is less to think about the thinking is more effective. It is necessary to restrict the consciousness and limit the mind to the present life in order to get the most satisfactory results. The same truth is embodied in that old saying that whoever is jack of all trades is master of none. Concentration alone can produce satisfactory results. If we would master the lessons of this life we must not take other lives within the field of consciousness. The very process of reincarnation is a coming out of the general into the particular, with the consequent narrowing of consciousness.