Edward Sapir (18841939). Language: An Introduction to the Study of Speech. 1921.
Stress is the most natural means at our disposal to emphasize a linguistic contrast, to indicate the major element in a sequence. Hence we need not be surprised to find that accent too, no less than sequence, may serve as the unaided symbol of certain relations. Such a contrast as that of go' between (one who goes between) and to go between' may be of quite secondary origin in English, but there is every reason to believe that analogous distinctions have prevailed at all times in linguistic history. A sequence like see' man might imply some type of relation in which see qualifies the following word, hence a seeing man or a seen (or visible) man, or is its predication, hence the man sees or the man is seen, while a sequence like see man' might indicate that the accented word in some way limits the application of the first, say as direct object, hence to see a man or (he) sees the man. Such alternations of relation, as symbolized by varying stresses, are important and frequent in a number of languages.30
It is a somewhat venturesome and yet not an altogether unreasonable speculation that sees in word order and stress the primary methods for the expression of all syntactic relations and looks upon the present relational value of specific words and elements as but a secondary condition due to a transfer of values. Thus, we may surmise that the Latin -m of words like feminam,dominum, and civem did not originally31 denote that woman, master, and citizen were objectively related to the verb of the proposition but indicated something