Johann Christian Reil was a German physician and medical professor, well-known and respected in his own time. Our interest here is in his views on the fundamental nature of living things, which were published in 1796 (Archiv für die Physiologie 1:8;1796) in an article “On the Vital Force”. Reil criticized the then-current vitalist concept that living organisms are distinguished from inanimate matter by virtue of their being infused with “vital forces” — an essentially supernatural explanation. Reil argued that the differences between animate and inanimate objects are entirely due to the properties of the matter they are made of. He conceived of living tissues as fundamentally mechanical in nature — a complex hierarchy of machinelike organs:

“The whole body consists of several large components; each component again [consists] of muscles, vessels, nerves; the muscle again of skin, fibres, vessels. What ingenious and composite mechanics! How many stages and arrangements of the same!… Here is only the whole a machine and the parts of the whole are natural bodies without purposeful development. To the regular mechanism of the animal body there also belongs both the coarse and the fine tissues of the fibres, the articulations of the large parts… Through the union of these countless organs, which by different stages combine together into a whole machine there are equally composite forces communicated to it. … It would be advantageous for theoretical and practical medicine if we could analyse the different kinds of degrees of organization, if we could reduce their most complex tissues to their most simple elements and if we were able to follow them from the original most elemental organ to the most complex animal organs. We would then be able, more happily, to analyse many phenomena and to reduce them more accurately to their principles.”

Reil’s biological views were basically modern ones — a surprising feat of insight from someone writing before the atomic and molecular nature of matter was at all understood.

Excerpted from a paper at the LeMoyne College Classic Chemistry site.

See also this biographical information at whonamedit.com