Lamarck, the Founder of Evolution: His Life and Work

by A. S. Packard

The mystical doctrine of a vital force was rife in Lamarck’s time. The chief starting point of the doctrine was due to Haller, and, as Verworn states, it is a doctrine which has confused all physiology down to the middle of the present century, and even now emerges again here and there in varied form.[116]

Lamarck was not a vitalist. Life, he says,[117] is usually supposed to be a particular being or entity; a sort of principle whose nature is unknown, and which possesses living bodies. This notion he denies as absurd, saying that life is a very natural phenomenon, a physical fact; in truth a little complicated in its principles, but not in any sense a particular or special being or entity.

He then defines life in the following words: “Life is an order and a state of things in the parts of every body possessing it, which permits or renders possible in it the execution of organic movement, and which, so long as it exists, is effectively opposed to death. Derange this order and this state of things to the point of preventing the execution of organic movement, or the possibility of its reëstablishment, then you cause death.” Afterwards, in the Philosophie zoologique, he modifies this definition, which reads thus: “Life, in the parts of a body which possesses it, is an order and a state of things which permit organic movements; and these movements, which constitute active life, result from the action of a stimulating cause which excites them.”[118]

For the science of all living bodies Lamarck proposed the word “Biology,” which is so convenient a term at the present day. The word first appears in the preface to the Hydrogéologie, published in 1802. It is worthy of note that in the same year the same word was proposed for the same science by G. R. Treviranus as the title of a work, Biologie, der Philosophie der lebenden Natur, published in 1802–1805 (vols. i.–vi., 1802–1822), the first volume appearing in 1802.

In the second part of the Philosophie zoologique he considers the physical causes of life, and in the introduction he defines nature as the ensemble of objects which comprise: (1) All existing physical bodies; (2) the general and special laws which regulate the changes of condition and situation of these bodies; (3) finally, the movement everywhere going on among them resulting in the wonderful order of things in nature.

To regard nature as eternal, and consequently as having existed from all time, is baseless and unreasonable. He prefers to think that nature is only a result, “whence, I suppose, and am glad to admit, a first cause, in a word, a supreme power which has given existence to nature, which has made it as a whole what it is.”

As to the source of life in bodies endowed with it, he considers it a problem more difficult than to determine the course of the stars in space, or the size, masses, and movements of the planets belonging to our solar system; but, however formidable the problem, the difficulties are not insurmountable, as the phenomena are purely physical—i.e., essentially resulting from acts of organization.

After defining life, in the third chapter (beginning vol. ii.) he treats of the exciting cause of organic movements. This exciting cause is foreign to the body which it vivifies, and does not perish, like the latter. “This cause resides in invisible, subtile, expansive, ever-active fluids which penetrate or are incessantly developed in the bodies which they animate.” These subtile fluids we should in these days regard as the physico-chemical agents, such as heat, light, electricity.

What he says in the next two chapters as to the “orgasme” and irritability excited by the before-mentioned exciting cause may be regarded as a crude foreshadowing of the primary properties of protoplasm, now regarded as the physical basis of life—i.e., contractility, irritability, and metabolism. In Chapter VI. Lamarck discusses direct or spontaneous generation in the same way as in 1802. In the following paragraph we have foreshadowed the characteristic qualities of the primeval protoplasmic matter fitted to receive the first traces of organization and life:

“Every mass of substance homogeneous in appearance, of a gelatinous or mucilaginous consistence, whose parts, coherent among themselves, will be in the state nearest fluidity, but will have only a consistence sufficient to constitute containing parts, will be the body most fitted to receive the first traces of organization and life.”