Possible Clues:

• Set of ideas formed from reasoning
• He is not practical enough to be in a conservative setting
• The words, as opposed to the practice
• Series of ideas seeking to explain something
• No practice is needed to get to the end of the story (6)
• General principles, as opposed to practice
• Explanation drawn from article on Circle line
• Idea of man in blue
• Thought male should be clothed in blue
• (Scientific) explanation