This final procedure is also called final per analogiam ( Latin ratiocinatio per analogiam ). Conclusion by analogy is often given evidential value (which, however, is only partially given at best) and is then referred to as proof of analogy.
Two basic types of inference by analogy result from the distinction between structural and functional analogy.
Antiquity to scholasticism
Analogism was already to be found as a paradeigma in Aristotle (in: first analytics). Theophrast called this final procedure the conclusion from hypothetical premises. The Epicureans regard this procedure ( o kata ten omoioteta tropos ) as a means from the apparitions to the unknown. With Boethius this conclusion is called exemplum . In the theological teachings of scholasticism , the process of theological needs gains a special valuation, especially with regard to positive statements about the divine conception according to the so-called analogy of being .
Conclusions by analogy according to scholasticism
Strictly speaking, analogism is not a proof - it consists in inferring the uncertain parts of an incompletely known system from the knowledge of a similar but fully known system. It is therefore primarily a tool for hypotheses education and "only heuristic value."
The conclusion by analogy can only be a proof if the two systems, i.e. the mapping and the mapped system, are isomorphic to each other , at least in the corresponding sub-area for which the proof is being made, and as long as the corresponding transformation rules are observed.
Conclusions by analogy have proven to be extremely fruitful and yielded important partial knowledge until the knowledge of the quantization of the energy and the orbits in the case of atomic structures made the essential difference between the relationships of a solar system and the atomic structure clear. This example also shows the problem of analogism: it is an inference of probability . In the borderline case, the analogy changes into isomorphism. The analogy that is first partially obtained, i.e. H. of consistency in some essential properties, structures, etc. a. totalize by assigning the appropriate elements . On the other hand, conclusions by analogy prove to be wrong if, in addition to all similarity or agreement, an essential difference between the phenomena posited in the analogy can be demonstrated.
No more psychic awareness
A well-known conclusion by analogy relates to consciousness :
- I feel in myself what it means to be conscious.
- I perceive similarities (for example in behavior) between myself and other people.
- All people are similar in this respect.
- From this I conclude that all people are conscious.
- Because all people have a consciousness like me, they will feel like me.
- It follows from this: What I find uncomfortable will also be uncomfortable for other people - or to put it literally: "What you don't want to be done to you, don't do it to anyone else."
The conclusion by analogy is an important form of reductive inference and represents a means of knowledge that has become important in many cases for the generation of scientific hypotheses. A historical example of this is the establishment of the first atomic models at the beginning of the 20th century, which were based on the assumption that the negative move charged electrons in circular or elliptical orbits around the positively charged atomic nucleus - each atom can thus be viewed as a microcosmic solar system. This assumption was based on conclusions by analogy with the facts that Coulomb's law , which indicates the force that two electrical charges exert on each other, structurally agrees with Newton's law of gravitation, from which in turn Kepler's laws of planetary orbits follow.
- Paul Bartha: Analogy and Analogical Reasoning. In: Edward N. Zalta (Ed.): Stanford Encyclopedia of Philosophy .
- Arnim Regenbogen, Uwe Meyer (Ed.): Dictionary of Philosophical Terms. Meiner, Hamburg 2005, ISBN 3-7873-1738-4 : Analogism