In his essay on “Metaphor” (in artificial languages), Rick Morneau argues that metaphors are best avoided when constructing a language (or when writing in a conlang). His arguments are sound, given that languages such as English, make heavy use of metaphor. Morneau gives examples of metaphors, such as “prices rise, soar, plummet, nosedive,” and “the work is uphill, downhil, or at a standstill.”
From an esoteric perspective, metaphor and simile are regularly used to help explain abstract concepts such as God, the Higher Self, the soul or spirit, etc. The Gospel of Thomas is a good example: (20) “[Heaven is] like a mustard seed…”; (50) “The Father’s kingdom is like a person who has [good] seed. …”; (96) “The Father’s kingdom is like [a] woman. …” While these are similes, a good example of a metaphor is the “dark night of the soul” described by Saint John of the Cross in a poem and follow-up commentary.
The benefit of metaphors is that they bring to mind images and related concepts, if the person reading/hearing the metaphor is familiar with the concept(s) that comprise the metaphor. For example, Assagioli’s Egg Diagram is a visual metaphor for the psyche, which is rich in symbolism. As with an actual egg, the “shell” is permeable t indicate that “stuff” can move between the boundaries, which delimit, rather than act as concrete separators. Some Psychosynthesis authors choose to refer to this diagram as the Oval Diagram, which to me is counterproductive as it removes the metaphorical associations, disempowering the symbol.
So, while I agree that metaphors may be unhelpful for many artificial languages I wonder if metaphors could be left out of an esoteric language. Obviously similes can be used extensively (“x is like y”), but metaphors such as the “dark night of the soul” seem so rich, especially when such things have been experienced. When the concept used as the metaphor is common, and likely cross-cultural, then it should be easily recognised. The abstract concept needs a different kind of understanding, often experiential. To me, “dark night of the soul” is a lot less awkward than “the journey of the soul is like travel during a dark night.”