Gunn, who praised his Stanford mentor Yvor Winters for keeping "both Rule and Energy in view, / Much power in each, most in the balanced two," found a productive tension – rather than imaginative restriction – in the technical demands of traditional poetic forms. He is one of the few contemporary poets (James Merrill would be another) to write serious poetry in heroic couplets – a form whose use in the twentieth century is generally restricted to light verse and epigrammatic wit. In the 1960s, however, he came to experiment increasingly with free verse, and the discipline of writing to a specific set of visual images, coupled with the liberation of free verse, constituted a new source of rule and energy in Gunn's work: a poem such as "Pierce Street" in his next collection, "Touch" (1967), has a grainy, photographic fidelity, while the title-poem uses hesitant, sinuous free verse to portray a scene of newly acknowledged intimacy shared with his sleeping lover (and the cat).