Well may a person, even with far greater pretensions than mine can be, hesitate to attempt the discussion of a subject which _frightened_ the illustrious Silvestre de Sacy; but as the Desátir is one of the principal sources from which the author of the Dabistán drew his account of the Persian religion and its divers sects――a considerable part of his work――I cannot dispense with presenting the subject in the state in which the discussions hitherto published, by very respectable critics, have left it. If I venture to offer a few remarks of my own upon it, it is only in the hope of provoking further elucidations by philologers who shall examine the Mahabadian text itself, and by arguments drawn from its fundamentals decide the important question――whether we shall have one language more or less to count among the relics of antiquity? Instead of following the order in which the questions are stated above, I will begin by that which appears to me the most important, namely: “the language in which the Desátir is written, is it nothing but a factitious language invented to support an imposture?” The forgery of a language, so bold an imposture, renders any other fraud probable; through a false medium no truth can be expected, nor even sought. But, in order to guard against the preconception of a forgery having taken place, a preconception the existence of which may, with too good a foundation, be apprehended, I shall first examine, as a general thesis, whether the invention of a language, by one individual or by a few individuals, is in itself probable and credible. I shall only adduce those principles which have received the sanction of great philologers, among whom it may be sufficient to name baron William Humboldt, and claim the reader’s indulgence, if, in endeavoring to be clear, I should not have sufficiently avoided trite observations. Tracing languages up to their first origin, it has been found that they are derived from sounds expressive of feelings; these are preserved in the roots, from which, in the progressive development of the faculty of speech, verbs, nouns, and the whole language, are formed. In every speech, even in the most simple one, the individual feeling has a connection with the common nature of mankind; speech is not a work of reflection: it is an instinctive creation. The infallible presence of the word required on every occasion is certainly not a mere act of memory; no human memory would be capable of furnishing it, if man did not possess in himself instinctively the key, not only for the formation of words, but also for a continued process of association: upon this the whole system of human language is founded. By entering into the very substance of existing languages, it appears evident that they are intellectual creations, which do not at all pass from one individual to others, but can only emerge from the coexisting self-activity of all.