Full Idea
There are theories of metaphors that require them to have literal meanings in order to achieve their metaphorical purpose, and those that do not.
Gist of Idea
Theories of metaphor divide over whether they must have literal meanings
Source
Ofra Magidor (Category Mistakes [2013], 3.5)
Book Reference
Magidor,Ofra: 'Category Mistakes' [OUP 2013], p.67
A Reaction
I take almost any string of proper language to have literal meaning (for compositional reasons), even if the end result is somewhat ridiculous. 'Churchill was a lion' obviously has literal meaning. And so does 'Churchill was a transcendental number'.