Jean-Baptiste Lamarck

Jean-Baptiste Lamarck (1744–1829) was a French naturalist who proposed the first coherent scientific account of how species change over time. Working half a century before Darwin, he argued that environmental pressures generate new needs in organisms, that those needs drive new behaviors and the use or disuse of organs, and that the resulting bodily changes are passed to offspring. He also coined the word biology (in his Hydrogeologie of 1802) to name the emerging science of living things, and he developed one of the most detailed materialist accounts of life (grounded in subtle physical fluids, cellular tissue, and graduated organisation) that the eighteenth-century tradition produced. His theory of transmutation was ultimately displaced by Darwin’s, but his questions about how living things relate to their environments, how complexity increases across generations, and what distinguishes life from non-life remained live problems well after his death.

Lamarck and the Word “Biology”

When Lamarck used the word biology for the first time in his Hydrogeologie (1802), he was naming a discipline that had not yet broken with its past (Canguilhem, 1994). Canguilhem notes that when he returned to the term in the preface to the Zoological Philosophy (1809), it appeared in the context of a treatise on animal organization “as one traverses their entire series from the most perfect to the most imperfect,” indicating that the object of the new biology was still, structurally, the same as Aristotle’s Historia animalium: a hierarchical series of living forms [cang-ir88-ch06-001]. The word was new; the problem it named was ancient.

Gottfried Treviranus coined Biologie independently in German in the same year, 1802. The term’s simultaneous emergence from two researchers working in different languages reflects the pressure that late Enlightenment natural history was under to reconstitute itself around the properties of living things as a class, rather than around the economic task of naming and cataloguing specimens (Lamarck, 1914).

The Critique of Artificial Classification

Lamarck’s point of departure in the Zoological Philosophy is a critique of what he calls the artificial devices of natural history: classes, orders, families, genera, and nomenclature are all inventions for human convenience, not divisions cut by nature (Lamarck, 1914). Nature, he insists, produces only individuals (Lamarck, 1914). The species, genera, and classes that naturalists argue over are abstractions imposed on a continuous natural reality, and confusing those abstractions with nature’s actual productions leads to fundamental philosophical errors, above all the error of believing that species are fixed and discrete entities (Lamarck, 1914).

The consequences of nomenclature are particularly sharp: assigning a fixed name to what is in reality a transitory state in an ongoing transformation reinforces the illusion of species fixity (Lamarck, 1914). This critique is not merely methodological. Lamarck’s attack on artificial classification is the opening move in an argument that the apparent fixity of species is an artefact of the limited duration of human observation relative to the vast stretches of geological time in which transformation actually occurs (Lamarck, 1914).

He distinguishes arrangement (placing objects in the order that nature herself follows) from classification, which is merely an artificial system to facilitate recognition and study (Lamarck, 1914). The natural arrangement is a linear gradation from the most complex to the simplest organisms. Linnaeus’s six-class system had lumped an enormous heterogeneous mass of organisms into a single class of “Worms” because there was no other place for them; Lamarck’s own 14-class system was designed to correct this by placing every group in its proper location along the series (Lamarck, 1914)(Lamarck, 1914).

Aristotle had been the first to attempt a general animal classification, Lamarck acknowledged, and his system was necessarily incomplete because he lacked sufficient anatomical knowledge of the lower organisms (Lamarck, 1914). Cuvier’s contribution to comparative anatomy was also acknowledged, though Lamarck distinguished his own task, establishing the natural series by organisation, from Cuvier’s more systematic work on internal anatomy (Lamarck, 1914).

The Distinction Between Living and Non-Living Bodies

Part Two of the Zoological Philosophy opens with a comparison of inorganic and living bodies that Lamarck treats as foundational. He enumerates nine fundamental differences, arguing that the gulf between them is radical: there is no graduated transition from non-living to living, only a sharp discontinuity (Lamarck, 1914). Among the nine differences, several are particularly consequential:

Among the consequences of this hiatus: every living body possesses a unity or individuality that pervades its entire mass and volume — a wholeness that cannot be reduced to or located in any of its component molecules, and which distinguishes it fundamentally from inorganic bodies whose aggregate properties are simply the sum of those of their constituent parts.(Lamarck, 1914) Living bodies must grow by intussusception (the incorporation of new material into existing structure), in contrast to inorganic bodies, which grow only by superficial accretion or juxtaposition (Lamarck, 1914). Every living body is formed from two necessarily co-existing parts: solid but supple containing parts, and liquid contained parts (Lamarck, 1914). Plants wholly lack irritability, which is the exclusive property of animals (Lamarck, 1914). Lamarck formalises this distinction in his definition of the animal: an organised living body with irritable parts that move either by stimulated irritability or by acts of will, a criterion that separates animals from plants whose parts are never irritable (Lamarck, 1914).

The philosophical implication Lamarck draws from this radical hiatus is precise: because the gulf between non-living and living is so large, spontaneous generation (the direct production of living bodies from inorganic matter) can only occur at the point where this gap is smallest, meaning only the very simplest organisms can be produced directly by nature (Lamarck, 1914). Everything else arises from reproduction.

What Life Consists Of

Lamarck’s definition of life is important in the history of biology because it refuses both crude materialism and any appeal to a vital force superadded to matter. Life, he writes, is “an order and state of things which permit of organic movements; and these movements constituting active life result from the action of a stimulating cause which excites them” (Lamarck, 1914). Life is not a substance, not a force, not a special ingredient; it is a functional state of organised matter, sustained by an external exciting cause.

He identifies three conditions that must be present for life to exist: supple containing parts (organs), contained fluids, and an exciting cause capable of producing organic movements (Lamarck, 1914). Lamarck offers a concise definition of life as “an order and state of things which permit of organic movements” resulting from the action of a stimulating cause (Lamarck, 1914). Against Richerand, he insists that life is not a collection of phenomena but itself a single phenomenon that gives rise to the collection of others we observe (Lamarck, 1914). Against Cabanis, Lamarck argues that not all vital movements are the result of impressions on sensitive parts; this can be true at most for animals that possess a nervous system, never for plants or polyps, and thus plants live without feeling (Lamarck, 1914).

Lamarck further grounds this position in experiment. Spallanzani’s demonstration that a rotifer could be revived after complete desiccation served, for Lamarck, as proof that life is precisely an order and state of things in a body, since it could be suspended and then renewed without the organism losing its capacity for living movement (Lamarck, 1914).

Lamarck is equally firm that matter as such cannot possess the property of feeling: sensation is not a simple attribute of organic substance but a phenomenon that results from the workings of an orderly system of organs (Lamarck, 1914).

The watch analogy captures his position: a stopped watch has all its parts, yet is not functioning; similarly, a dead body has all its organs yet is not alive (Lamarck, 1914). Life depends not on the parts alone but on the state of those parts: specifically, the state in which organic movements can be maintained.

Lamarck states that faculties common to all living bodies do not need any special organs, while peculiar faculties require special organs (Lamarck, 1914). Among the vital faculties, reproduction derives its origin like growth from nutrition and intensifies when the faculty of growth declines (Lamarck, 1914). Both animal and vegetable organisation have, as a result of the power of life, worked out their own advancing complexity from the simplest to the most complex (Lamarck, 1914). Every faculty is based upon some special organ or system of organs, and organisation gradually becomes more complex as one passes from the simplest animal to the most perfect (Lamarck, 1914).

The resulting picture of animal life is hierarchical. Lamarck describes a four-tier ordering of animal faculties: from the most imperfect animals that lack feeling altogether, through those with sensation but only a dependent will, to those with confused ideas and a degree of free will, and finally to the most perfect, which possess thought and judgment (Lamarck, 1914).

The Exciting Cause of Organic Movements: Subtle Fluids

Lamarck argues that life requires a special exciting cause capable of producing organic movements (Lamarck, 1914). This exciting cause is a force that animates the organs and serves as the spring driving all vital movements (Lamarck, 1914).

Caloric, the subtle fluid of heat, is identified as the first cause of life. It penetrates living bodies and maintains in them the state of orgasm (a term of art in eighteenth-century physiology meaning a baseline vital tension or erethism of the supple internal parts) without which no organic movement can take place (Lamarck, 1914)(Lamarck, 1914). Lamarck states this priority plainly: caloric is the first cause of life because it produces and maintains orgasm, and without orgasm no living body could exist (Lamarck, 1914). The cause of orgasm is principally caloric in two forms: the caloric of the surrounding environment and the caloric constantly produced inside the bodies of many animals by their own vital processes (Lamarck, 1914). Electric fluid is the proximate exciting cause, directly producing muscular contraction and transmitting nervous influence from one part to another (Lamarck, 1914).

[GAP: Claim that Lamarck’s account is naturalistic] [GAP: Contrast with ancient philosophers’ vital principle] [GAP: Transition to a direct criticism from Lamarck] Lamarck identifies caloric and the electric fluid as the two essential elements of the exciting cause: caloric maintains orgasm, electric fluid excites movement (Lamarck, 1914).

The ancient philosophers felt the necessity for a special exciting cause of organic movements; but not having sufficiently studied nature, they sought it beyond her; they imagined a vital principle, a perishable soul for animals, and even attributed the same to plants; thus in place of positive knowledge, which they could not attain from want of observations, they created mere words to which are attached only vague and unreal ideas. (Lamarck, 1914)

This positions Lamarck as a naturalist who wanted to integrate life into a materialist framework while refusing to reduce living phenomena to simple mechanism.

Lamarck attributes orgasm to an invisible, expansive, penetrating fluid that produces tension in the parts (Lamarck, 1914). He criticizes Cabanis and Richerand for treating this orgasm as a kind of sensibility, arguing it is more convenient to give it a particular name (Lamarck, 1914). Furthermore, he reasons that organic movements are due to the action and reaction of parts, and that all such processes are mechanical and subject to physical laws (Lamarck, 1914).

Cellular Tissue as the Universal Matrix

The mechanism by which subtle fluids produce complex organisation passes through cellular tissue, which Lamarck regards as the universal matrix in which all organisation has been cast: every organ in every living body is formed from and within cellular tissue by the movement of contained fluids through it (Lamarck, 1914). In the Zoological Philosophy, Lamarck identifies cellular tissue as the specific means by which nature progressively creates and develops organs — not a passive substrate but an active site of organisational production.(Lamarck, 1914)

cellular tissue is the universal matrix of all organisation, and … without this tissue no living body could continue to exist. (Lamarck, 1914)

The simplest living bodies consist only of a mass of cellular tissue without vessels, glands, or viscera (Lamarck, 1914). Cellular tissue is the matrix in which all organs are formed through the movement of fluids (Lamarck, 1914).

Lamarck’s fluid-movement theory of organisation is also the key to his account of how modifications are preserved and transmitted: the state of organisation in every living body has been gradually acquired by the increasing influence of fluid movement (Lamarck, 1914), and every organisation and new shape so acquired is then preserved and transmitted by reproduction until further modifications are added (Lamarck, 1914). The very simple organisation of imperfect animals like infusorians and polyps consists only of cellular tissue with slow internal fluid movements (Lamarck, 1914).

Gradation of Animal Organisation

Lamarck argues that nature has formed a true scale in each kingdom as regards the increasing complexity of organisation, perceptible in the main groups but not in species (Lamarck, 1914).

nature, by giving existence in the course of long periods of time to all the animals and plants, has really formed a true scale in each of these kingdoms as regards the increasing complexity of organisation; but … the gradations in this scale … are only perceptible in the main groups of the general series, and not in the species or even in the genera. (Lamarck, 1914)

Lamarck criticizes Aristotle’s two-class division (animals with blood, animals without), arguing that the first outline of a classification was made in the wrong direction, from most complex to simplest (Lamarck, 1914).

Lamarck’s repeated reference to “nature” in this context carries a specific philosophical weight: by nature he means the general and immutable order established by the Sublime Author, together with the sum total of the laws to which it is subject — a formulation that situates his naturalism within a framework of rational theism rather than atheistic mechanism.(Lamarck, 1914)

Read from most complex to least complex, the series illustrates degradation (the successive simplification of organisation); read from least to most complex, it illustrates gradation (the progressive addition of organs and faculties) (Lamarck, 1914)(Lamarck, 1914). The gradation is not strictly regular, because environmental pressure deflects it (Lamarck, 1914).

If the factor which is incessantly working towards complicating organisation were the only one which had any influence on the shape and organs of animals, the growing complexity of organisation would everywhere be very regular. But it is not; nature is forced to submit her works to the influence of their environment, and this environment everywhere produces variations in them. (Lamarck, 1914)

At the simplest end of the series, the natural death of an organism results from the progressive hardening of organs over time: nutrition assimilates more solid materials than the body volatilises, and the cumulative deposition of insoluble residues eventually renders the parts too rigid for organic movement (Lamarck, 1914).

Spontaneous Generation and the Simple Living Body

Lamarck accepts spontaneous generation (the direct production of living bodies from inorganic matter) but restricts it sharply (Lamarck, 1914). Nature creates life directly only in the simplest organisms, at the boundary where the hiatus between living and non-living is smallest; she does not produce complex organisms directly (Lamarck, 1914). Ancient philosophers concluded that heat was necessary for the maintenance of life and could even create both life and organization (Lamarck, 1914).

The ancients were correct in attributing to nature the faculty of direct generation, but mistakenly applied it to many bodies that cannot be produced by such generation, implying a restricted spontaneous generation (Lamarck, 1914). Lamarck also offers a population-level observation: the rapid multiplication of small species is limited by predation, short lifespans, and temperature changes, preventing them from overrunning the globe (Lamarck, 1914). Nature directly creates only the rudiments of organisation, and only at the beginning of the animal and vegetable scales (Lamarck, 1914). All natural bodies are productions of nature, which must have begun with the simplest, the veriest rudiments of organisation (Lamarck, 1914).

Inheritance of Acquired Characteristics

Lamarck’s two laws of hereditary change are the most-discussed part of his theory, though in the Zoological Philosophy they are embedded within the broader account of organisation, cellular tissue, and fluid movement rather than standing apart as isolated principles.

The first law holds that species are mutable over time: changes in the environment bring about changes in the needs of animals living in that environment, and these changes of needs lead to changes of actions, which lead in turn to changes in organs (Lamarck, 1914). The second law holds that the characters thus acquired are preserved by reproduction in all individuals submitted to the same influences (Lamarck, 1914). Together, these constitute what later writers would call the doctrine of the inheritance of acquired characteristics.

In Lamarck’s own formulation,(Lamarck, 1914) the first law concerns the effect of use and disuse on the individual organism over its lifetime:

First Law. In every animal which has not passed the limit of its development, a more frequent and continuous use of any organ gradually strengthens, develops and enlarges that organ, and gives it a power proportional to the length of time it has been so used; while the permanent disuse of any organ imperceptibly weakens and deteriorates it, and progressively diminishes its functional capacity, until it finally disappears.

The second law(Lamarck, 1914) specifies how those acquired modifications are transmitted to the next generation:

Second Law. All the acquisitions or losses wrought by nature on individuals, through the influence of the environment in which their race has long been placed, and hence through the influence of the predominant use or permanent disuse of any organ; all these are preserved by reproduction to the new individuals which arise, provided that the acquired modifications are common to both sexes, or at least to the individuals which produce the young.

The illustration that has fixed Lamarck’s name in popular memory comes a few pages later,(Lamarck, 1914) in the giraffe, an animal whose anatomy he treats not as a special creation but as the legible record of a long behavioral history:

It is interesting to observe the result of habit in the peculiar shape and size of the giraffe (Camelo-pardalis): this animal, the largest of the mammals, is known to live in the interior of Africa in places where the soil is nearly always arid and barren, so that it is obliged to browse on the leaves of trees and to make constant efforts to reach them. From this habit long maintained in all its race, it has resulted that the animal’s fore-legs have become longer than its hind legs, and that its neck is lengthened to such a degree that the giraffe, without standing up on its hind legs, attains a height of six metres (nearly 20 feet).

Read together, the two laws and the giraffe example show that Lamarck’s account moves in two directions at once: from environment to behavior to organ, and from organ back to inheritance. Neither law works in isolation. The first without the second would produce only a population of individually trained animals whose acquisitions died with them; the second without the first would have nothing to preserve.

The mechanism is the cellular tissue theory: organisational modifications produced by the sustained movement of fluids through cellular tissue leave channels and patterns that reproduction then transmits (Lamarck, 1914). In the most complex organisms, this mechanism reaches into emotional and psychological life: prolonged strong emotions can produce lasting organic changes in the abdominal organs, and these changes can in turn be transmitted through reproduction (Lamarck, 1914)(Lamarck, 1914). Lamarck thereby extends inheritance of acquired characters beyond mere physical use and disuse to include psychosomatic modifications produced by sustained states of the inner feeling.

The Inner Feeling and Will

In animals with a highly developed nervous system, Lamarck identifies a faculty he calls the inner feeling (sentiment intérieur), which he describes as the singular faculty by which animals experience inner emotions called forth by needs and external or internal causes; from it arises the power for performing diverse actions (Lamarck, 1914).

one of the most remarkable faculties conferred by the nervous system on all animals in which it is highly developed; … that singular faculty, with which certain animals and man himself are endowed, consisting in the capacity to experience inner emotions called forth by the needs and various causes external or internal; from this faculty arises the power for performing diverse actions. (Lamarck, 1914)

The inner feeling has two aspects: it is simultaneously the result of obscure internal sensations and the source of a faculty for producing movements in response to needs, making it both receptive and executive and therefore the seat of animal agency (Lamarck, 1914).

Inner emotions consist in general agitations of the free parts of the nervous fluid; when sudden and powerful, the individual is mastered by them rather than dominating them (Lamarck, 1914). The feeling of existence results from the confused assembly of inner sensations constantly arising throughout the animal’s life (Lamarck, 1914). This continuous and intimate inner feeling constitutes the ego with which all merely sensitive animals are imbued without knowing it, while those with intelligence may notice it through thought and attention (Lamarck, 1914).

The principle that every unused faculty gradually degenerates until it becomes almost extinct applies to the moral sensibility of those habituated to dissimulation (Lamarck, 1914). In such individuals, moral sensibility is nearly absent, and they do not even esteem it in persons who still possess it to a moderate degree (Lamarck, 1914).

Physical sensibility is not a property of any individual organic part; rather, it is a function of the entire sensitive system (Lamarck, 1914)(Lamarck, 1914). Lamarck is careful to distinguish sensibility from irritability: the two are very different in character and arise from unlike causes — sensibility demands a special organ and constitutes a systemic function, while irritability is only a local phenomenon at the site of stimulation.(Lamarck, 1914) Every impression, internal or external, immediately causes an agitation throughout the sensitive system, which gives rise to a reaction brought back to the common nucleus (Lamarck, 1914). This mechanism explains why separate parts of the body appear sensitive only by a kind of hallucination, as the general effect is referred to the part affected (Lamarck, 1914).

In the most complex animals, Lamarck distinguishes three separately organised systems: one for muscular movement, one for sensation, and one for intelligence, each with its own specific apparatus and capable of operating independently of the others (Lamarck, 1914).

Lamarck and Darwin

Lamarck’s Zoological Philosophy preceded Darwin’s On the Origin of Species by fifty years. Both accounts share a commitment to the mutability of species across vast stretches of time (Lamarck, 1914), and both reject the view that species are natural kinds fixed in creation. The differences are fundamental. Darwin’s primary mechanism, natural selection operating on random variation, requires no intentionality, no felt need, and no use-inheritance; Lamarck’s mechanism requires all three. Canguilhem notes that Darwin’s milieu is primarily biotic (the first milieu an organism inhabits is an entourage of other living beings), making living competition rather than the organism’s own felt needs the driver of evolutionary change (Canguilhem, Georges, 1952/2008). This is a structural difference in how the two theories understand the organism-environment relationship.

Lamarck’s theory of milieu is, in Canguilhem’s reading, genuinely vitalist in a way that mechanist readings miss: it posits need as the mediating term between environmental change and organic response, so adaptation in Lamarck is an effort rather than a mechanical consequence (Canguilhem, Georges, 1952/2008). Canguilhem emphasises that when Lamarck speaks of the action of circumstances or milieus on organisms, he does not mean direct mechanical action of the exterior milieu on living tissue; he means action mediated through need, a subjective notion that implies reference to a positive pole of vital values.

The historical relationship is complicated by the fact that Darwin acknowledged Lamarck’s priority (he listed Lamarck among his predecessors in the historical sketch appended to later editions of the Origin) while arguing that the mechanism of use-inheritance was insufficient to explain the full range of biological phenomena, and that natural selection acting on random variation could do the explanatory work without it.

Bergson’s Reading

Henri Bergson’s Creative Evolution (1911) engages Lamarck as one of the two major evolutionary frameworks, alongside Darwinian natural selection, that are inadequate to the phenomena of life but point in different directions toward what Bergson regards as the true account. Bergson argues that the similarity of complex organs on independent evolutionary lines (the vertebrate and mollusc eye being the most striking case) is inexplicable by pure mechanism (accidental variation plus selection) or by pure Lamarckian adaptation (Bergson, 1911). If Lamarckism were correct, the independent development of the same complex structure on unrelated evolutionary lines would require the same sequence of needs, the same sequence of efforts, the same sequence of organic responses: a coincidence so elaborate as to be incredible.

Bergson’s objection to Lamarckism is not that effort and use-inheritance are non-existent but that they are insufficient as sole explanatory principles. Adaptation explains the sinuosities of evolutionary movement but not its general direction or the movement itself (Bergson, 1911). The independent convergence of complex structures on separate lines points, for Bergson, to what he calls the élan vital, a common original impetus that precedes the divergence of evolutionary lines and supplies the directive force that neither Lamarck’s felt need nor Darwin’s selection can fully provide.

This reading preserves what Bergson takes to be the genuine insight in Lamarck (that organisms are active rather than passive, that something like effort or orientation is real in evolutionary history) while arguing that it needs to be grounded in an account of what generates that effort in the first place.

Canguilhem’s Reading

The notion of milieu was imported into biology from Newtonian mechanics in the late eighteenth century; it began as a concept for a fluid intermediary between physical bodies, not as a relational biological concept (Canguilhem, Georges, 1952/2008). Lamarck, inspired by Buffon, introduced it into biology, but he used it only in the plural (Canguilhem, Georges, 1952/2008).

Canguilhem’s point is that mechanist readings of Lamarck distort his actual position. A strictly mechanist usage of the milieu concept leads logically to a theory of animal-machines, organisms passively determined by their environments, “persons without personality.” Lamarck’s theory, by contrast, posits need (a subjective notion implying reference to a positive pole of vital values) as the mediating term, which is a vitalist move (Canguilhem, Georges, 1952/2008). The organism in Lamarck is not an input-output machine receiving environmental signals and producing adaptive responses; it is a being with needs that constitute its relationship to its environment as much as it is constituted by that environment.

Neo-Lamarckism in Psychiatry and Psychoanalysis

Lamarck’s theory of inherited acquired characteristics had an afterlife in French psychiatry, as French neo-Lamarckianism viewed evolution as mediated between the internal physiology of an organism and its environment (Ian Dowbiggin, 1991). This framework provided the conceptual infrastructure for Bénédict-Augustin Morel’s 1857 Treatise on Degeneracy, which proposed that madness was hereditary biological decay transmitted across generations via Lamarckian inheritance (Andrew Scull, 2015). Morel’s account was the medical counterpart of Lamarckian biology, explaining how accommodation to a pathogenic environment could produce mental and physical disorders over successive generations (Ian Dowbiggin, 1991).

The alienist Emile Renaudin had argued as early as the 1850s that heredity seemed to accumulate the acquired pathological characteristics of each generation; he cited alcoholism, which appeared in epidemic proportions during the Second Empire, as one of the acquired characteristics contributing to the growing wave of hereditary disease (Ian Dowbiggin, 1991). The physiologist C. E. Brown-Séquard’s experiments between 1843 and 1870, in which deliberately induced nervous-system injuries in guinea pigs produced hereditary epilepsy in their offspring, were cited extensively by French alienists as experimental evidence for the Lamarckian framework (Ian Dowbiggin, 1991). A group of American scientists advanced the law of acceleration and retardation, which neo-Lamarckians listed as one of two modes of species development alongside natural selection (Haller, 1981); figures such as Edward Drinker Cope, Nathaniel Shaler, and Joseph LeConte epitomized late nineteenth-century scientific racial attitudes by rejecting natural selection for a Lamarckian approach (Haller, 1971). More broadly, the majority of late nineteenth-century American scientists who wrote about race were either Spencerian social Darwinists or neo-Lamarckians, and both camps shared an optimistic view of Caucasian racial progress grounded in the inheritability of environmentally shaped characteristics (Haller, 1971).

In psychoanalysis, Lamarckian inheritance provided Freud with the theoretical bridge he needed between the individual unconscious and the history of the species. The Wolf-Man case illustrated the explanatory pressure: Freud’s reconstruction of a scene witnessed at eighteen months seemed implausible even to him, and he hedged by arguing that even if the witnessing had not occurred, Lamarckian heredity could account for the child’s memory of such an event (Makari, George, 2008). Totem and Taboo, Jung’s Transformations of the Libido, and Ferenczi’s Thalassa all relied on the premise that the individual unconscious could carry traces of the species’ evolutionary history, a premise grounded in Lamarckian assumptions about the inheritance of acquired psychic dispositions. The discrediting of Lamarckian heredity by the 1920s (Mendel’s experiments had turned the tide around 1900, and by 1910 the gene had been conceptualised and linked to the chromosome) destroyed this extraclinical avenue for understanding the unconscious and drove psychoanalysis toward reliance on the individual clinical encounter and child observation as alternative empirical forums (Makari, George, 2008).

Legacy and Reception

Lamarck’s reception was complicated from the start by his relationship with Cuvier, who dominated French biology in the early nineteenth century and whose theory of fixed types and catastrophist geology was incompatible with Lamarckian transformism. Cuvier’s authority meant that Lamarck’s theory was professionally marginalised in France even during his lifetime; he died in poverty and near-blindness in 1829.

The Lamarckian-Darwinian debate that dominated evolutionary biology from 1859 onward was in large part a question of mechanism. Darwin’s selectionist account required no felt need, no use-inheritance, no directing tendency in organisms. The neo-Lamarckian tradition, represented in France, Britain, and America by writers who found natural selection insufficient, preserved some form of the doctrine that organisms actively shape their own evolutionary trajectories through sustained use and effort, and that these modifications are in some sense heritable. The experimental refutation of soft inheritance (the acquisition of heritable characters during an individual’s lifetime) through Weismann’s germ plasm theory and the subsequent development of Mendelian genetics in the early twentieth century drove this position from mainstream biology, though it retained influence in psychiatry, psychoanalysis, and social thought considerably longer.

The question of what, precisely, Lamarck was committed to in his theory of milieu and need (whether it was a fully vitalist or a proto-mechanist account) remains contested in the secondary literature, and Canguilhem’s rehabilitation of Lamarck as a genuinely vitalist thinker represents one influential reading that challenges dismissive treatments of him as merely a precursor who got the mechanism wrong.

See Also

• Charles Darwin
• Vitalism
• Transmutation of Species
• Spontaneous Generation
• Georges Cuvier
• Henri Bergson
• Georges Canguilhem
• Degeneration Theory
• Neo-Lamarckism
• Inheritance of Acquired Characteristics

Sources

All claims cite evidence cards from:

• Lamarck, J.-B. (1809/1914). Zoological Philosophy. Trans. H. Elliot. London: Macmillan. [Source ID: lamarck-zoological-philosophy-1914] — Primary authority; all lam14- claims are primary-translation provenance.
• Bergson, H. (1911). Creative Evolution. Trans. A. Mitchell. London: Macmillan. [Source ID: bergson-creative-evolution-1911]
• Canguilhem, G. (2008). Knowledge of Life. Trans. S. Geroulanos & D. Ginsburg. New York: Fordham University Press. [Source ID: canguilhem-knowledgeoflife-2008]
• Canguilhem, G. (1988). Ideology and Rationality in the History of the Life Sciences. Trans. A. Goldhammer. Cambridge, MA: MIT Press. [Source ID: canguilhem-ideology-rationality-life-1988]
• Canguilhem, G. (1994). A Vital Rationalist: Selected Writings from Georges Canguilhem. New York: Zone Books. [Source ID: canguilhem-vital-rationalist-1994]
• Dowbiggin, I. (1991). Inheriting Madness: Professionalization and Psychiatric Knowledge in Nineteenth-Century France. Berkeley: University of California Press. [Source ID: dowbiggin-inheritingmadness-1991]
• Makari, G. (2008). Revolution in Mind: The Creation of Psychoanalysis. New York: HarperCollins. [Source ID: makari-revolutioninmind-2008]
• Scull, A. (2015). Madness in Civilization. Princeton: Princeton University Press. [Source ID: scull-madnesscivilization-2015]
• Haller, J.S. (1981). American Medicine in Transition. Urbana: University of Illinois Press. [Source ID: haller-americanmedicine-1981]
• Haller, J.S. (1971). Outcasts from Evolution. Urbana: University of Illinois Press. [Source ID: haller-outcasts-from-evolution-1971]

Editorial Notes

Gaps the encyclopaedia compiler flagged for future evidence work, collected from inline markers in the body and frontmatter.

Lamarck and Darwin