1973, Previously Unpublished
In Seven Types of Ambiguity , Mr. Empson quotes in full and discusses at length Sir Philip Sidney's double sestine “Strephon and Klaius” .
This is a poem of twelve six‑line stanzas with a three‑line envoi, each of the six line‑endings, A, B, C, D, E, F, repeating themselves in different order in the following five stanzas, then to recommence and go through the same cycle, finally coming together in the initial order in the envoi. Mr. Empson writes:
“The poem beats, however rich its orchestration, with a wailing and immovable monotony, for ever upon the same doors in vain. Mountaines, vallies, forrests; musique, evening, morning; it is at these words only that Klaius and Strephon pause in their cries; ... and in tracing their lovelorn pastoral tedium through thirteen repetitions, with something of the aimless multitudinousness of the sea on a rock, we seem to extract all the meaning possible from these notions; ...”
A factor to which Mr. Empson does not call attention is the contribution to wavelike monotony made by the formal quality of the repetition. The line‑endings follow the sequence 1‑2‑4‑5‑3‑6 and da capo. This is the order for A; for B correspondingly 2‑4‑5‑3‑6‑1; for C 3‑6‑1‑2‑4‑5, etc. The geometry is shown in the diagram, suggesting indeed waves of the sea, but waves of an exceeding regularity.
Perhaps there is a closer similitude with the figure of a dance of six partners. Each in turn proceeds in a devious route from the head of the line to the foot, then with a single leap again to the head. In this course each gives right hand and left hand to all the other partners in turn, with three of them first one hand and then the other, with two of them either twice right or twice left. The changing relationships in successive stanzas are shown in the table.
The bracketed numbers show the stanzas in which the named word, by moving from last to first in order, is next to itself. These changing partnerships have a decisive effect on the emotional tone of each successive stanza, and even to some extent on its content of meaning. The feminine endings, required by the classic model, add to the rhythmic monotony.
As already noted, the position of A, B, C, D, E and F in each line of each stanza is completely described by a single six‑digit number, 124536. If we assume that, to fulfil the spirit of a sestine, the sixth ending of any one stanza must become the first of the next, then any sestine formula must take the form i .... 6. There are 24 different ways of filling the intervening places in the formula, but only five others (beside 124536) which are as efficient in mating each partner with each of the others with 'bot‑h right and left band. These are 125346, 142356, 145326, 152346, 154236. No sequence is possible in which each partner would meet each with both right and left hand. It seems possible that perhaps the 124536 order, once discovered (perhaps by the Provencal troubadour Arnaud Daniel), was continued in use by later poets without further experimentation, as the only one thought possible.
The present writer has discovered no use of any of the five alternatives to the 124536 pattern. This is the form given as a model by Stillman . It is also the form used by Sidney  in his other sestine, the form used by Dante  in his triple sestine, and by Petrarch  in two sestines. The only part of the sestine in which there is variation from a strict rule is in the envoi. According to Stillman there must be repetition within the three lines as well as at the end, to accommodate all six endings; and they should be in the order BEDCFA. However, Dante, using the same thematic line‑endings throughout, has three envois for his triple sestine; for the first he has BADFEC and for the other two *A*F*C, dropping B, D, and E, and having no repetition within the lines. Internal repetition in the envoi is retained by Petrarch. The two envois have the forms ABDECF and ABCDEF, in the latter case bringing back the order of the first stanza. It is this latter form that seems to have been the pattern for Sydney.
 Seven Types of Ambiguity by William Empson, 1947 (first published 1930), London, Chatto and Windus, pp. 34‑38.
 The Complete Poems of Sir Philip Sidney, ed. Alexander B. Grosart, 1877, London, Chatto and Windus, vol. II, pp. 197‑202.
 The Poet's Manual and Rhyming Dictionary by Francis Stillman, 1966, London, Thames and Hudson, pp. 70‑73.  Grosart, l.c., III, Pp. 48‑50.
 Il Canzoniere di Dante Alighieri ed. Pietro Fraticelli, 1911. Firenze, G. Barbera, pp. 158‑162.
 Francesco Petrarca Rime Trionfi e Poesie Latine ed. F. Neri, G. Martellotti, E. Bianchi, N. Sapegno, 1951. Milano, Napoli, Riccardo Ricciardi, pp. 45‑46, 309‑310.
Tables and Notes