Paul Ricoeur wrote considerably on the concept of metaphors. One major work was
The Rule of Metaphor: Multi-disciplinary Studies of the Creation of Meaning in Language
He described six contrasts between his understanding of metaphors and the, at the time at least, common understanding of metaphors.
1. Fundamental unit of meaning. It was (is?) common to think of the “word” as the fundamental unit of meaning. Ricoeur states that the fundamental unit is the sentence. This actually makes sense since words, at best, have a locus or cloud of meanings. The “meaning” of a word is indeterminate until it is placed within a sentence. This is particularly relevant for metaphors since metaphors are groups or words, or sentences. No individual word (that I know of) is a metaphor in and of itself.
We might laugh at the quote from “Through the Looking Glass” (Lewis Carroll), but it is in many ways quite true:
“When I use a word,’ Humpty Dumpty said in rather a scornful tone, ‘it means just what I choose it to mean — neither more nor less.’
’The question is,’ said Alice, ‘whether you can make words mean so many different things.’
’The question is,’ said Humpty Dumpty, ‘which is to be master — that’s all.”
2. Literal versus Figurative. It has been common to think of metaphors as figurative language and tied, necessarily to allegories. Some would argue, in fact, that an allegory is an extended metaphor. Ricoeur argued that metaphors are not figurative. They take two words or concepts that are literal, and then juxtapose them to create a literary tension between them. Metaphors are not figurative but express meaning through the interaction of literal concepts.
This is really really important. Consider the statement “The Lord is my Shepherd” from Psalm 23. Shepherd is a metaphor. It is not figurative. The term Lord here refers to God (of course, “Lord” when associated with “God” is also a metaphor, but let’s leave that alone at this time). God is literal. Shepherd is literal. The two are logically incompatible. But one gains an understanding of who God is by the “tension” of the incompatibility. In fact, a good metaphor is TRUE as long as it is also NOT TRUE. That is, “The Lord is my Shepherd” is a valid metaphor in part because “The Lord is NOT my Shepherd.” God doesn’t walk around the hills and fields with a bunch of sheep… feeding, tending, shearing sheep.
Consider what we might call the three-fold roles of Jesus— prophet, priest, and king. Two of these roles are metaphors. Jesus was literally, non-metaphorically, a prophet. That was His acknowledged role during His 3-year ministry in Galilee and Judea. Jesus never literally served as a priest, nor as a king. Even in heaven, He will not have those literal roles. That is because the roles have literal meaning within the confines of human culture. For example, the “head bee” in a hive we might call the Queen… but the actual role is considerably different from a real queen. Jesus is metaphorically a priest, taking on some roles that we think of in terms of a literal priest. Jesus is metaphorically a king, taking on some roles that we think of in terms of a literal king. The difference between prophet, priest, and king is found in the negation. Because priest and king are metaphors, there is tension in the literal senses. Therefore, it is correct, on some level, that Jesus is NOT a priest or is NOT a king. But it would not be correct to say that Jesus was not a prophet. The most you could say is that Jesus was more than a prophet.
3. Cognitive versus Affective. Once one accepts a metaphor as literal rather than figurative, then one moves from a cognitive understanding to a more affective understanding. The value of a metaphor is in its shock… its emotive impact. When we hear that “The Lord is my Shepherd,” it is supposed to shock us. We are not supposed to be entirely comfortable with it. It is supposed to challenge us. When Jesus described God as “Our Father,” we are supposed to be challenged by such a (fairly outrageous) metaphor. When the metaphor loses affective impact, it has lost much of its power. Worse, when it shifts to theological dogma… something further is lost. I would argue that we are supposed to be shocked in the metaphor of Christ: “This is my body” and “This is my blood.” The transition over the centuries of the first millennium from literal metaphor to figure and then to literal dogma destroyed the impact. Even those of us who reject the literal dogma of transubstantiation, or the figurative dogma of consubstantiation still struggle with restoring the original metaphoric impact.
4. Meaning. Some argue that metaphors are a substitution for literal language. However, following the logic of the above points, metaphors are semantic innovations… a way of developing complex meaning structures. When Jesus is described as “The Lamb of God” we know that Jesus is not a sheep. The term “lamb” is meant literally, but the tension of connecting Jesus with a lamb brings up huge theological and historical data within the Old Testament and Judaism. Metaphors are not used to replace literal meaning, but to draw out complex and nuanced meanings.
5. Translatability. Some argue that metaphors are simply a replacement of propositional speech. This may not be impossible… but it is impractical in many cases. When it is fully possible, the metaphor is probably unnecssary. When a person is described as a “snake in the grass,” perhaps it could be substituted with something like, “The person is a deceptive individual whose motives appear benign until he acts to cause great damage.” In that case, the “snake in the grass” probably has more of a poetic or ornamental role. When Jesus described himself as a “gate,” perhaps that could be said to be simply stylistic… he could have said it without metaphor. But to take “Jesus is the Lamb of God” and remove all metaphors from it and replace it with simple propositional language… that would pretty much be impossible. The metaphoric language is necessary.
6. Function. This really is a continuation of the previous point. Metaphors are not simply ornaments of language. The fact that they can’t be adequately translated, removing the metaphors (normally at least) means that they are more than ornaments. That being said, of course, a good metaphor does greatly add to style, of course… and might be used even if it is not absolutely necessary from a functional standpoint. Consider Hebrews 4:12. “Living indeed is the Word of God, and active and sharper than any two-edged sword.” This is a series of metaphors. God’s word is not “living,” is not “active,” and is not “sharp.” But it provides useful imagery metaphorically that helps us understand some important things about God’s Word. However, even if one could convey the same message without metaphors, why would one want to? There is a beauty in the language. Read Psalm 23 or Psalm 1 for beautiful metaphors… having both ornamental and semantic roles.
Of course, there are dangers with metaphors. They can easily confuse people. In Franz Kafka’s Metamorphosis, the main character transitioned from a metaphoric insect to an actual insect. But we can do the same thing (figuratively) when we read metaphors carelessly and either concretize them, or find the wrong lessons from the creative tension within the metaphors.