The ''Generation of Animals'' (or ''On the Generation of Animals'';
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
: ''Περὶ ζῴων γενέσεως'' (''Peri Zoion Geneseos'');
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
: ''De Generatione Animalium'') is one of the biological works of the
Corpus Aristotelicum
The Corpus Aristotelicum is the collection of Aristotle's works that have survived from antiquity through medieval manuscript transmission. These texts, as opposed to Aristotle's works that were lost or intentionally destroyed, are technical ph ...
, the collection of texts traditionally attributed to
Aristotle
Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of phil ...
(384 – 322BC). The work provides an account of animal
reproduction
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...
,
gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregna ...
and
heredity
Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic inform ...
.
Content
''Generation of Animals'' consists of five books, which are themselves split into varying numbers of chapters. Most editions of this work categorise it with
Bekker numbers
Bekker numbering or Bekker pagination is the standard form of citation to the works of Aristotle. It is based on the page numbers used in the Prussian Academy of Sciences edition of the complete works of Aristotle and takes its name from the ed ...
. In general, each book covers a range of related topics, however there is also a significant amount of overlap in the content of the books. For example, while one of the two principal topics covered in book I is the function of
semen
Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Semen i ...
(''gone'', ''sperma''), this account is not finalised until partway through book II.
Book I (715a - 731b)
Chapter 1 begins with Aristotle claiming to have already addressed the parts of animals, referencing the author’s work
of the same name. While this and possibly his other
biological works, have addressed three of the
four causes
The four causes or four explanations are, in Aristotelian thought, four fundamental types of answer to the question "why?", in analysis of change or movement in nature: the material, the formal, the efficient, and the final. Aristotle wrote th ...
pertaining to animals, the
final
Final, Finals or The Final may refer to:
*Final (competition), the last or championship round of a sporting competition, match, game, or other contest which decides a winner for an event
** Another term for playoffs, describing a sequence of cont ...
,
formal, and
material
Material is a substance or mixture of substances that constitutes an object. Materials can be pure or impure, living or non-living matter. Materials can be classified on the basis of their physical and chemical properties, or on their geologi ...
, the
efficient cause
The four causes or four explanations are, in Aristotelian thought, four fundamental types of answer to the question "why?", in analysis of change or movement in nature: the material, the formal, the efficient, and the final. Aristotle wrote th ...
has yet to be spoken of. He argues that the efficient cause, or “that from which the source of movement comes” can be addressed with an inquiry into the generation of animals. Aristotle then provides a general overview of the processes of reproduction adopted by the various genera, for instance most ‘
blooded
''Blooded'' is a novel written by Christopher Golden and Nancy Holder, based on the U.S. television series ''Buffy the Vampire Slayer
''Buffy the Vampire Slayer'' is an American supernatural drama television series created by writer and di ...
’ animals reproduce by
coition of a male and female of the same
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
, but cases vary for ‘bloodless’ animals.
The
reproductive organs
A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, a ...
of males and females are also investigated. Through chapters 2-5 Aristotle successively describes the general reproductive features common to each sex, the differences in
reproductive parts among blooded animals, the causes of differences of
testes
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testoster ...
in particular, and why some animals do not have external reproductive organs. The latter provides clear examples of Aristotle’s
teleological
Teleology (from and )Partridge, Eric. 1977''Origins: A Short Etymological Dictionary of Modern English'' London: Routledge, p. 4187. or finalityDubray, Charles. 2020 912Teleology" In ''The Catholic Encyclopedia'' 14. New York: Robert Appleton ...
approach to causation, as it is applied to
biology
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary i ...
. He argues that the male
hedgehog
A hedgehog is a spiny mammal of the subfamily Erinaceinae, in the eulipotyphlan family Erinaceidae. There are seventeen species of hedgehog in five genera found throughout parts of Europe, Asia, and Africa, and in New Zealand by introducti ...
has its testes near its
loin
The loins, or lumbus, are the sides between the lower ribs and pelvis, and the lower part of the back. The term is used to describe the anatomy of humans and quadrupeds, such as horses, pigs, or cattle. The anatomical reference also applies to p ...
, unlike the majority of vivipara, because due to their spines hedgehogs mate standing upright. The hedgehog’s form is that of an animal able to use its spines for self-defence, and so its reproductive organs are situated in such a way as to complement this.
Chapter 6 describes why
fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...
and
serpents copulate in a short space of time, and chapter 7 provides an explanation for why serpents intertwine during coition. Chapters 8-11 focus on female reproductive organs, and in particular the differences in viviparous and
oviparous
Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...
production of young, and the differing states of the
eggs
Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...
produced by ovipara. This is continued in chapters 12 and 13, where Aristotle discusses the reasons the
uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The uter ...
is internal and the testes external, and their locations among various species. Concluding this section on the reproductive parts of animals is an overview from chapters 14-16 of the generative faculties of
crustacea
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...
,
cephalopods
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, an ...
, and
insects
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...
. This section contains an admission of an observational uncertainty, with Aristote stating that observations of insect coition are not yet detailed enough to classify into types.
The remainder of Book I (chapters 17 – 23) is concerned with providing an account of semen and its contribution to the generative process. The primary conclusions reached in this section are, firstly, that semen is not a bodily waste product, but “a residue of useful nutriment”, and that because the bodily emissions produced by females during copulation are not of a similar nutritive character, semen must be the efficient cause of offspring.
Book II (731b – 749a)
Chapters 1-3 of Book II continue the discussion of semen from the end of Book I. As a result of questioning potential ways in which the particular parts of animals might come to be formed, such as semen containing small versions of the bodily organs, before settling on the idea that semen contributes the potential (''dunamis'') for the parts to come into being as they are. This is the basis for the imparting of the
soul
In many religious and philosophical traditions, there is a belief that a soul is "the immaterial aspect or essence of a human being".
Etymology
The Modern English noun ''soul'' is derived from Old English ''sāwol, sāwel''. The earliest attes ...
upon the material substratum present in the egg, as the female reproductive residue itself contains no active principle for the motion required to form an
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
. Aristotle’s conception of the soul should not be mistaken for one which takes the soul to be a non-physical substance separate to the body. It instead comprises the ability for some function to be performed, which in the case of bodily development means the ability for organs to perform their bodily functions. Scholar Devin Henry describes Aristotle’s view as follows:
"Aristotelian souls are not the sorts of things that are capable of being implanted in bodily organs from without (except perhaps intellectual soul). Soul is not an extra ingredient added to the organ over-and-above its structure. Once there is a properly constructed organ it straightaway possess the corresponding soul-function in virtue of its structure."
The generative capacity of semen in imparting the soul is its heat, with semen itself being “a compound of breath and water”. It is the component of breath (''
pneuma
''Pneuma'' () is an ancient Greek word for "breath", and in a religious context for "spirit" or "soul". It has various technical meanings for medical writers and philosophers of classical antiquity, particularly in regard to physiology, and is a ...
'') that shapes the material provided by the female into the correct form.
The mechanics of the development of the embryo take up much of chapters 4-7, with Aristotle addressing first the different stages of development at which vivipara and ovipara expel their young. In chapter 5 the theory of soul-imparting is amended slightly, as observations of
wind-eggs show that the female, unassisted, is able to impart the nutritive aspect of the soul, which Aristotle claims is its lowest portion''.'' Chapter 6 addresses the order in which the parts of an embryo come about, and in chapter 7 Aristotle argues that, contrary to what
Democritus
Democritus (; el, Δημόκριτος, ''Dēmókritos'', meaning "chosen of the people"; – ) was an Ancient Greek pre-Socratic philosopher from Abdera, primarily remembered today for his formulation of an atomic theory of the universe. No ...
apparently thought, that “children are nourished in the uterus by sucking some lump of flesh”, in actuality unborn vivipara are nourished by the
umbilical cord
In placental mammals, the umbilical cord (also called the navel string, birth cord or ''funiculus umbilicalis'') is a conduit between the developing embryo or fetus and the placenta. During prenatal development, the umbilical cord is physiologic ...
. Chapter 8 discusses cross-breeding of species, and the
sterility of
mules.
Book III (749a – 763b)
Book III covers non-viviparous embryonic development. The first four chapters provide a description and explanation of eggs, while in chapters 5-7 Aristotle responds to other ideas about eggs and some observational difficulties in providing an empirical account of all eggs. The final chapters cover the development of hitherto unmentioned animals.
Chapter 1 is on the subject of bird eggs, with Aristotle providing explanations for why different birds produce different amounts of eggs, why some birds produce wind-eggs, and why bird eggs are sometimes of two colours. Following an explication of the formation of eggs and how they provide nutrition for the embryo in chapter 2, in chapter 3 Aristotle compares the eggs of
birds
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
against those of fish. The descriptive account of eggs is completed in chapter 4, which describes the growth of some eggs after they have been laid.
![Alaska_Weasel](https://upload.wikimedia.org/wikipedia/commons/7/76/Alaska_Weasel.jpg)
Chapters 5 and 6 are a response to what Aristotle takes to be falsely-held beliefs of other
scientists
A scientist is a person who conducts scientific research to advance knowledge in an area of the natural sciences.
In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophica ...
concerning the process of procreation. For example,
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, ...
apparently held that
weasels
Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets and European mink. Members of this genus are small, active predators, with long and slender b ...
give birth from their mouths because “the young of the weasel are very small like those of the other fissipeds, of which we shall speak later, and because they often carry the young about in their mouths. Aristotle states instead that weasels have the same uteruses as other
quadrupeds
Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor' ...
, and there is nothing to connect the uterus to the mouth, so such a claim as Anaxagoras’ must be unfounded.
Chapters 7-10 cover the generative processes of
selachians
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimo ...
, cephalopods, crustacea, insects and
bees
Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamil ...
, in successive order. Chapter 11 concerns the generation of
testacea
Testacea may refer to:
* a former order of rhizopods, which consisted of testate amoeboid organisms.
* a former group of shelled molluscs and other invertebrates, created by Linnaeus and roughly corresponding to the colloquial term '' seashell'' ...
, which are said to generate spontaneously. While it is possible for some of the Testacea, such as mussels, to emit a
liquid
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, a ...
slime which can form others of the same kind, they are also formed “in connexion with putrefaction and admixture of rain-water.”
Book IV (763b – 778a)
Book IV is primarily on the topic of biological inheritance. Aristotle is concerned with both the similarities between the offspring and parents and the differences that can arise within a particular species as a result of the generative process. Chapters 1 is an account of the origin of the sexes. Aristotle considers the sexes to be “the first principles of all living things”. Given this, the sex of an embryo is determined entirely by the potency of the fertilising semen, which contains the male principle. If this semen lacks heat in fashioning the material present in the female then the male principle cannot take hold, and therefore its opposite principle must take hold. In chapter two Aristotle provides pieces of observational evidence for this, including the following:
"Again, more males are born if copulation takes place when north than when south winds are blowing; for animals’ bodies are more liquid when the wind is in the south, so that they produce more residue – and more residue is harder to concoct; hence the semen of the males is more liquid and so is the discharge of the menstrual fluids in women."
In chapter 3 Aristotle provides the primary elements of his theory of inheritance and resemblances. Utilising the account of the function of semen from Book II Aristotle describes how the movement of semen upon the proto-embryonic material gives rise to particular traits inherited from one’s ancestors. Semen contains the general male principle, and contains in addition that of the
particular
In metaphysics, particulars or individuals are usually contrasted with universals. Universals concern features that can be exemplified by various different particulars. Particulars are often seen as concrete, spatiotemporal entities as opposed to a ...
male whose semen it is, so
Socrates
Socrates (; ; –399 BC) was a Greek philosopher from Athens who is credited as the founder of Western philosophy and among the first moral philosophers of the ethical tradition of thought. An enigmatic figure, Socrates authored no te ...
’ semen will contain his particular genetic traits. In fashioning the material the semen imparts, or does not impart, genetic traits in the same way as the determination of sex, where a resemblance to the father will be imparted onto the material if the semen is of a suitable temperature, provided the male principle has established the sex as male. If instead the male principle was hot enough to be imparted but not that of the particular male, Socrates, was not then the movement may either put forth a resemblance to the mother, or it could relapse into that of the father of the father or some other non-immediate ancestor.
![Grooming_monkeys](https://upload.wikimedia.org/wikipedia/commons/b/b5/Grooming_monkeys.jpg)
Chapter 4 develops this theory for the cases of
deformities
A deformity, dysmorphism, or dysmorphic feature is a major abnormality of an organism that makes a part of the body appear or function differently than how it is supposed to.
Causes
Deformity can be caused by a variety of factors:
*Arthritis an ...
, and why different animals produce different amounts of
offspring
In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This ca ...
. The former is due to malformed reproductive material present in the female, and for the latter it is particular relations of the size of the animal, the moisture of reproductive materials, and the heat of semen. Chapter 5 presents the causes of
superfetation
Superfetation (also spelled superfoetation – see fetus) is the simultaneous occurrence of more than one stage of developing offspring in the same animal.
In mammals, it manifests as the formation of an embryo from a different menstrual cycle wh ...
, which is an inadequate separation of multiple young during gestation. Chapters 6 and 7 focus on the causes of other birth defects, and why males are allegedly more likely to suffer from
defects. Chapters 8-10 concern the production of
milk
Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digestion, digest solid food. Immune factors and immune ...
, why animals are born headfirst, and on the length of gestation being proportional to the length of life, respectively.
Book V (778a – 789b)
Aristotle takes Book V to be an investigation of “the qualities by which the parts of animals differ.” The subjects addressed by this book are a miscellaneous range of animal parts, such as
eye colour
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...
(chapter 1),
body hair
Body hair, or androgenic hair, is the terminal hair that develops on the human body during and after puberty. It is differentiated from the head hair and less visible vellus hair, which is much finer and lighter in color. The growth of androge ...
(chapter 3) and the
pitch of the voice (chapter 7). The apparent lack of a single causal scheme or subject matter for these discrete topics has led to disagreement in how this book relates to the rest of the ''Generation of Animals''. Some scholars take the Book only to be concerned only with
material causes of intra-species differences that arise later in development, in contrast with the earlier books’ systematic use of teleology. Others have suggested that Book V does utilise causation other than material to a considerable extent.
Criticisms
Feminist Critiques
''Generation of Animals''’ account of animal reproduction has been taken by some scholars to be
misogynistic
Misogyny () is hatred of, contempt for, or prejudice against women. It is a form of sexism that is used to keep women at a lower social status than men, thus maintaining the societal roles of patriarchy. Misogyny has been widely practiced fo ...
, along with several of Aristotle’s extant works. It has been argued that Aristotle’s description of semen as the determining factor in the formation of the child in its likeness shows the female to be inherently defective; a malformed man. On this view an embryo will only take on a female form if the formative semen is insufficiently heated, and so arises only of a non-ideal conceptive process. A related critique is that Aristotle’s conception of formation as having semen as its only active principle treats all reproduction as
androcentric
Androcentrism (Ancient Greek, ἀνήρ, "man, male") is the practice, conscious or otherwise, of placing a masculine point of view at the center of one's world view, culture, and history, thereby culturally marginalizing femininity. The related a ...
. According to Tuana, where Aristotle does refer to female capacities to influence the generative process it is in construing
menses
Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of horm ...
as kinds of deficient semen, rather than something else entirely. Aristotle is also said to have made a number of misogynistic claims about what is required for conception to occur, such as the following:
Aristotle seems to be assuming that seminal fluids are those that are emitted when sufficient levels of sexual pleasure are experienced. Since women conceive without experiencing pleasure in intercourse, and thus without emitting such fluids, and, conversely, experience pleasure in intercourse and thereby emit such fluids without conceiving, there is reason to deny the association of these fluids with semen.
Whether Aristotle’s biology is sexist the extent posed has been questioned by Henry. He argues that when Aristotle says the generation of a male resembling the father to be the ‘most natural’ (''malista pephuken'') he means this in the sense of ‘the most likely’ rather than ‘the proper’. Therefore it is not the case that the male is taken to be the norm, and females are deformed and defective. Additionally, he states that Aristotle does not think that the generation of a male is the end (''telos'') to which reproduction aims, because the aim of reproduction is the continuance of the species, not a particular sex
Although… the males of the species are responsible for ''transmitting'' the species form, that doesn’t mean the form being transmitted includes the property of being male. For Aristotle, males and females embody the same ''sex-less'' species form.
Nielsen
takes issue with Henry’s account, arguing that while females do embody the species form in Aristotle’s account, they are defective members of their species. This is because the reproductive system is said by Aristotle to have the purpose of producing nutritive semen, which a female is unable to do, thus making them defective in the same manner as young boys or
eunuchs
A eunuch ( ) is a male who has been castrated. Throughout history, castration often served a specific social function.
The earliest records for intentional castration to produce eunuchs are from the Sumerian city of Lagash in the 2nd millennium ...
.
References
Works by Aristotle
Works Cited
* Aristotle. ‘Generation of Animals’. In ''The Complete Works of Aristotle'', edited by Jonathan Barnes, translated by A. Platt, 6. print., with Corr., 1:pp. 1111–1218. Bollingen Series, 71,2. Princeton, N.J: Princeton Univ. Pr, 1995.
* Henry, Devin. ‘Generation of Animals’. In ''A Companion to Aristotle'', edited by Georgios Anagnostopoulos, pp. 368–84. Blackwell Companions to Philosophy 42. Chichester, U.K. ; Malden, MA: Wiley-Blackwell, 2009.
* Henry, Devin. . ‘How Sexist Is Aristotle’s Developmental Biology?’ ''Phronesis'' 52, no. 3 (2007): pp. 251–69.
* Katayama, Errol G. ''Aristotle on Artifacts: A Metaphysical Puzzle''. SUNY Series in Ancient Greek Philosophy. Albany, NY: State University of New York Press, 1999.
* Lennox, James G. ‘Aristotle’s Biology’. Stanford Encyclopedia of Philosophy, 16 July 2021.
https://plato.stanford.edu/archives/fall2021/entries/aristotle-biology/.
* Nielsen, Karen. ‘The Private Parts of Animals: Aristotle on the Teleology of Sexual Difference’. ''Phronesis'' 53, no. 4–5 (2008): pp. 373–405.
* Tuana, Nancy. ‘The Weaker Seed. The Sexist Bias of Reproductive Theory’. ''Hypatia'' 3, no. 1 (1988): pp. 35–59.
External Links
''Generation of Animals'' by Aristotle translated by Arthur Platt* {{librivox book , title=Generation of Animals , author=ARISTOTLE