Homoeomeria was a doctrine in the philosophy of the ancient Greek

Anaxagoras Anaxagoras (; grc-gre, Ἀναξαγόρας, ''Anaxagóras'', "lord of the assembly"; 500 – 428 BC) was a Pre-Socratic Greek philosopher. Born in Clazomenae at a time when Asia Minor was under the control of the Persian Empire, ...

, as claimed by the Roman atomist

Lucretius Titus Lucretius Carus ( , ; – ) was a Roman poet and philosopher. His only known work is the philosophical poem '' De rerum natura'', a didactic work about the tenets and philosophy of Epicureanism, and which usually is translated into E ...

. It was assumed that the

atoms Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas ...

constituting a substance must themselves have the salient observed properties of that substance: so atoms of

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...

would be wet, atoms of

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

would be hard, atoms of

wool Wool is the textile fibre obtained from sheep and other mammals, especially goats, rabbits, and camelids. The term may also refer to inorganic materials, such as mineral wool and glass wool, that have properties similar to animal wool. ...

would be soft, etc. This doctrine depends on the

fallacy of division A fallacy of division is an informal fallacy that occurs when one reasons that something that is true for a whole must also be true of all or some of its parts. An example: # The second grade in Jefferson Elementary eats a lot of ice cream # Ca ...

. Professor Fleeming Jenkin wrote that: "we may with the exercise of a good deal of fancy see in the doctrine of homoeomeria, which taught that all things contained the materials of everything else in a latent state, a foreshadowing of the chemical theory which proves that our bodies are made of the same chemical materials as peas, cabbages, &c., but it requires an elastic imagination to link the old and new creed together."''Memoir of Fleeming Jenkin'', by R. L. Stevenson. Papers by Fleeming Jenkin, edited by Sir Sidney Colvin, James Alfred Ewing. P. 198.

References

obsolete scientific theories {{sci-hist-stub