In the English language, the phrase, "Intelligent Design," is not a generic, descriptive phrase, but a specific name of a thoroughly discredited side show within the Creationist movement. You should not be using this term to describe Darwin's thoughts on origins. The term, "intelligent design" was never used by Darwin and was only invented quite recently to wrap up in misleading terminology an old argument for the existence of the traditional Christian God. You have to be very careful about using the term, design, at all when describing the mechanisms of evolution, and process thought can entirely dispense with the word.