As he wrote of ‘a thousand invisible cords’ and ‘innumerable unbreakable cords’, and of those ‘that cannot be broken’, he mulled over a concept of nature where everything was connected. Every tree, flower, insect, bird, stream or lake seemed to invite him ‘to learn something of its history and relationship’, and the greatest achievements of his first summer in Yosemite, he said, were ‘lessons of unity and inter-relation’.2
