ELDER BROTHERS AND MAHATMAS
The most intelligent being in the universe, man, has never, then, been without a friend, but has a line of elder brothers who continually watch over the progress of the less progressed, preserve the knowledge gained through aeons of trial and experience, and continually seek for opportunities of drawing the developing intelligence of the race on this or other globes to consider the great truths concerning the destiny of the soul. These elder brothers also keep the knowledge they have gained of the laws of nature in all departments, and are ready when cyclic law permits to use it for the benefit of mankind. They have always existed as a body, all knowing each other, no matter in what part of the world they may be, and all working for the race in many different ways. In some periods they are well known to the people and move among ordinary men whenever the social organization, the virtue, and the development of the nations permit it. For if they were to come out openly and be heard of everywhere, they would be worshipped as gods by some and hunted as devils by others. In those periods when they do come out some of their number are rulers of men, some teachers, a few great philosophers, while others remain still unknown except to the most advanced of the body.
The Elder Brothers of Humanity are men who were perfected in former periods of evolution. These periods of manifestation are unknown to modern evolutionists so far as their number is concerned, though long ago understood by not only the older Hindus, but also by those great minds and men who instituted and carried on the first pure and undebased form of the Mysteries of Greece. The periods, when out of the Great Unknown there come forth the visible universes, are eternal in their coming and going, alternating with equal periods of silence and rest again in the Unknown. The object of these mighty waves is the production of perfect man, the evolution of soul, and they always witness the increase of the number of Elder Brothers; the life of the least of men pictures them in day and night, waking and sleeping birth and death, "for these two, light and dark, day and night, are the world"s eternal ways." [footnote: Bhagavad-Gita, Chap. viii.]
In every age and complete national history these men of power and compassion are given different designations. They have been called Initiates, Adepts Magi, Hierophants, Kings of the East, Wise Men. Brothers, and what not. But in the Sanskrit language there is a word which, being applied to them, at once thoroughly identifies them with humanity. It is Mahatma. This is composed of Maha great and Atma soul; so it means great soul, and as all men are souls the distinction of the Mahatma lies in greatness.... For all through Hindu literature Mahatmas are often spoken of, and in parts of the north of that country the term is common. In the very old poem the Bhagavad-Gita, revered by all Hindu sects and admitted by the western critics to be noble as well as beautiful, there is a verse reading, "Such a Mahatma is difficult to find."[Bhagavad-Gita, Chap. vii.]
From Chapter 1 - The Ocean of Theosophy William Q. Judge