Analogy is an effective form of reasoning adopted in scientific practice. Indeed, hypotheses are often formulated by applying analogical inferences based on alleged similarities with previously successful cases. As a matter of fact, analogical thinking proves to be a powerful heuristic tool, both in the context of discovery and in the context of justification, or confirmation, of scientific hypotheses, especially in physics. Furthermore, thanks to the ability of making complicated concepts more accessible by drawing upon already familiar similar cases, it represents a useful pedagogical vehicle to transfer scientific knowledge both in school teaching and in the popularization of science. Yet, the conceptual and formal status of analogies remains an open problem in nowadays philosophy of science.

The putative scheme for analogical inferences holds that, given two systems sharing a number of properties, one can infer that if the source system is known to possess an additional property, then the target system ought to possess a similar property as well. Nevertheless, this conclusion is not logically warranted. There thus arises an outstanding philosophical question: that is, how can we draw plausible analogies in science? Such a question becomes even more pressing in those domains of physics where we have limited empirical access to a target system, as it happens in the sub-atomic quantum world as well as in the large-scale structure of spacetime.

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