In studying psychology anyone who is acquainted with the Sanskrit tongue must know how valuable that language is for precise and scientific dealing with the subject. The Sanskrit, or the well-made, the constructed, the built-together, tongue, is one that lends itself better than any other to the elucidation of psychological difficulties. Over and over again, by the mere form of a word, a hint is given, an explanation or relation is suggested. The language is constructed in a fashion which enables a large number of meanings to be connoted by a single word, so that you may trace all allied ideas, ,or truths, or facts, by this verbal connection, when you are speaking or using Sanskrit. It has a limited number of important roots, and then an immense number of words constructed on those roots.
Now the root of the word yoga is a word that means " to join," yuj, and that root appears in many languages, such as the English--of course, through the Latin, wherein you get jugare, jungere, "to join"--and out of that a number of English words are derived and will at once suggest themselves to you: junction, conjunction, disjunction, and so on. The English word "yoke" again, is derived from this same Sanskrit root so that all through the various words, or thoughts, or facts connected with this one root, you are able to gather the meaning of the word yoga and to see how much that word covers in the ordinary processes of the mind and how suggestive many of the words connected with it are, acting, so to speak, as sign-posts to direct you along the road to the meaning. In other tongues, as in French, we have a word like rapport, used constantly in English; " being en rapport," a French expression, but so Anglicized that it is continually heard amongst ourselves. And that term, in some ways, is the closest to the meaning of the Sanskrit word yoga; "to be in relation to"; "to be connected with"; "to enter into"; "to merge in"; and so on: all these ideas are classified together under the one head of "Yoga". When you find Sri Krishna saying that "Yoga is equilibrium," in the Sanskrit He is saying a perfectly obvious thing, because Yoga implies balance, yoking and the Sanskrit of equilibrium is "samvata--togetherness"; so that it is a perfectly simple, straightforward statement, not connoting anything very deep, but merely expressing one of the fundamental meanings of the word He is using. And so with another word, a word used in the commentary on the Sutra I quoted before, which conveys to the Hindu a perfectly straightforward meaning: "Yoga is Samadhi." To an only English-knowing person that does not convey any very definite idea; each word needs explanation. To a Sanskrit-knowing man the two words are obviously related to one another. For the word yoga, we have seen, means "yoked together," and Samadhi derived from the root dha, "to place," with the prepositions sam and a, meaning "completely together". Samadhi, therefore, literally means " fully placing together," and its etymological equivalent in English would be " to compose " (com=sam; posita= place). Samadhi therefore means "composing the mind," collecting it together, checking all distractions. Thus by philological, as well as by practical, investigation the two words yoga and samadhi are inseparably linked together. And when Vyasa, the commentator, says: "Yoga is the composed mind," he is conveying a clear and significant idea as to what is implied in Yoga. Although Samadhi has come to mean, by a natural sequence of ideas, the trance-state which results from perfect composure, its original meaning should not be lost sight of.
Thus, in explaining Yoga, one is often at a loss for the English equivalent of the manifold meanings of the Sanskrit tongue, and I earnestly advise those of you who can do so, at least to acquaint yourselves sufficiently with this admirable language, to make the literature of Yoga more intelligible to you than it can be to a person who is completely ignorant of Sanskrit