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.

Its Relation to Indian Philosophies

Let me ask you to think for a while on the place of Yoga in its relation to two of the great Hindu schools of philosophical thought, for neither the Westerner nor the non-Sanskrit-knowing Indian can ever really understand the translations of the chief Indian books, now current here and in the West, and the force of all the allusions they make, unless they acquaint themselves in some degree with the outlines of these great schools of philosophy, they being the very foundation on which these books are built up.  Take the Bhagavad-Gita.  Probably there are many who know that book fairly well, who use it as the book to help in the spiritual life, who are not familiar with most of its precepts.  But you must always be more or less in a fog in reading it, unless you realise the fact that it is founded on a particular Indian philosophy and that the meaning of nearly all the technical words in it is practically limited by their meaning in philosophy known as the Samkhya.  There are certain phrases belonging rather to the Vedanta, but the great majority are Samkhyan, and it is taken for granted that the people reading or using the book are familiar with the outline of the Samkhyan philosophy.  I do not want to take you into details, but I must give you the leading ideas of the philosophy.  For if you grasp these, you will not only read your Bhagavad-Gita with much more intelligence than before, but you will be able to use it practically for yogic purposes in a way that, without this knowledge, is almost impossible.