It is largely due to him that writers developed that formalism of style, that precise, almost mathematical elegance, miscalled classicism, which ruled English literature for the next century.[174] Another thing which the reader will note with interest in Restoration literature is the adoption of the heroic couplet; that is, two iambic pentameter lines which rime together, as the most suitable form of poetry. Waller,[175] who began to use it in 1623, is generally regarded as the father of the couplet, for he is the first poet to use it consistently in the bulk of his poetry. Chaucer had used the rimed couplet wonderfully well in his _Canterbury Tales_, but in Chaucer it is the poetical thought more than the expression which delights us. With the Restoration writers, form counts for everything. Waller and Dryden made the couplet the prevailing literary fashion, and in their hands the couplet becomes "closed"; that is, each pair of lines must contain a complete thought, stated as precisely as possible. Thus Waller writes: The soul's dark cottage, battered and decayed, Lets in new light through chinks that time has made.[176] That is a kind of aphorism such as Pope made in large quantities in the following age. It contains a thought, is catchy, quotable, easy to remember; and the Restoration writers delighted in it. Soon this mechanical closed couplet, in which the second line was often made first,[177] almost excluded all other forms of poetry. It was dominant in England for a full century, and we have grown familiar with it, and somewhat weary of its monotony, in such famous poems as Pope's "Essay on Man" and Goldsmith's "Deserted Village." These, however, are essays rather than poems. That even the couplet is capable of melody and variety is shown in Chaucer's _Tales_ and in Keats's exquisite _Endymion_. These four things, the tendency to vulgar realism in the drama, a general formalism which came from following set rules, the development of a simpler and more direct prose style, and the prevalence of the heroic couplet in poetry are the main characteristics of Restoration literature. They are all exemplified in the work of one man, John Dryden. JOHN DRYDEN (1631-1700) Dryden is the greatest literary figure of the Restoration, and in his work we have an excellent reflection of both the good and the evil tendencies of the age in which he lived. If we can think for a moment of literature as a canal of water, we may appreciate the figure that Dryden is the "lock by which the waters of English poetry were let down from the mountains of Shakespeare and Milton to the plain of Pope"; that is, he stands between two very different ages, and serves as a transition from one to the other.