Remarks on Colour line that 'There is no such thing as phenomenology, though there are phenomenological problems.' He was content to regard Goethe's observations as a kind of logic or geometry. Wittgenstein took his examples from the Runge letter included in the "Farbenlehre", e.g. "White is the lightest colour", "There cannot be a transparent white", "There cannot be a reddish green", and so on. The logical status of these propositions in Wittgenstein's investigation, including their relation to physics, was discussed in Jonathan Westphal's "Colour: a Philosophical Introduction" (1991). Although "Remarks on Colour" is considered difficult on account of its fragmentation, his last work,
Operation Grapes of Wrath the grapes of wrath are stored; He hath loosed the fateful lightning of His terrible swift sword: His truth is marching on.</poem> The irony (and potential controversy) of an Israeli military operation being named after a Christian religious doctrine was not entirely lost on the Israeli press. However, most commentators either believed the title was a reference from the Torah or that the phrase merely referred to John Steinbeck's novel of the same name, "The Grapes of Wrath". Operation Grapes of Wrath Operation "Grapes of Wrath" () is the Israeli Defense Forces code-name (referred to as April War by Hezbollah)