There are an increasing number of books available about the importance of metaphor in thought, many of which provide strong supporting arguments and evidence for the use of Clean Language with metaphor in Symbolic Modelling.
We’ll assume you’ve already invested in Clean Language: Revealing Metaphors and Opening Minds by Wendy Sullivan and Judy Rees, and perhaps (if you are interested in coaching or therapy) Penny Tompkins and James Lawley’s excellent book, Metaphors in Mind.
Some of our favourite books make metaphor the main focus: for example, Lakoff and Johnson. Their book Metaphors We Live By is now somewhat dated, but is still a classic. We more strongly recommend their more recent books such as Philosophy In The Flesh by George Lakoff and Mark Johnson, or Women, Fire and Dangerous Things by George Lakoff.
If you enjoy a fairly academic – though still entertaining – writing style The Stuff of Thought by Steven Pinker if a fascinating read. This book argues that metaphor, together with the ability to combine ideas into new ones, is what makes us human.
For a more business-focussed look at metaphor and its importance, with lots of practical examples, try How Customers Think by Gerald Zaltman. And for a passionate endorsement of metaphor and its role in creativity, design and much else, Daniel Pink’s A Whole New Mind is excellent.