analogy and metaphor

We say that something A is analogous to something B if, in some relevant respect, A is similar to but not identical with B. This is the basic relation upon which the use of analogy in various kinds of reasoning depends. We speak of reasoning by analogy when on the basis of some similarity which we discern between two things or processes or properties, or what you will, we infer some other similarity. Reasoning by analogy is a special case of inductive reasoning since we must be wary of the possibility that the further similarities which are presupposed in our inference may not actually obtain. Like all inductive inference reasoning by analogy is stepping from the known to the unknown. Clearly, then, analogical reasoning is not demonstrative or deductive.