Tag: Ancient science

115. On the Generation of Animals (De Generatione Animalium) by Aristotle (c.350 BC)

115. On the Generation of Animals (De Generatione Animalium) by Aristotle (c.350 BC)

Aristotle now goes into more detail on the reproductive anatomy, behaviour, embyrology, and development of animals.

My copy is from the 2 volumes of the works of Aristotle which form part of the series Great Books of the Western World, published by Encyclopaedia Britannica in 1952.

My thoughts:  I might mention in passing that I have given each of my Aristotle posts the Latin name of the work as well as the English. Of course Aristotle was Greek, but the works are well known since Roman times by scholars using these titles. They also have  a numerical cataloguing system called Bekker numbers which indicate page numbers across the entire surviving works, but I haven’t used them. (It seems like Aristotle may have written works on botany as well, but they have either been lost or never started)

The great misconception this work is probably remembered for is Aristotle’s belief that some lower animals are spontaneously generated from “decaying earth and excrements” rather than sexual reproduction. These are the ones that change their forms (e.g. maggots into flies) as Aristotle reasons that true parents would naturally give rise to offspring that looked like themselves whereas these creatures do not. This belief in apparent spontaneous generation is perhaps understandable from a botanic point of view – after all, fungi grow on dead trees without apparent seeds.

Some of the other things Aristotle got slightly wrong:

  • Birds and terrestrial reptiles lay “perfect” eggs (having a hard covering or shell) by internally heating the egg to remove the moisture from the membrane, requiring some part of the female to heat up inside,
  • Both males and females produce semen,
  • Men must hold their breath before ejecting semen, (well, maybe 🙂 )
  • Anatomically he missed the ovaries entirely

But he did get some things right despite popular beliefs of his contemporaries to the contrary. For instance, other natural philosophers (including Hippocrates) thought semen was produced in all parts of the body (pangenesis), allowing children to look like their parents by direct inheritance of traits such as facial features copied from the original in situ.  Aristotle rejected this on several grounds. He also seemed to grasp that the inherited parts provided by both parents were potential traits rather than actuals.

He also conjectures that the male semen acted on the purest part of the female’s menstrual flow (which is her imperfect semen) to create an embryo. (Unflatteringly he compared the action to rennet acting on milk causing it to curdle). He gradually comes to the conclusion that the female provides the elements required for  a “nutritive soul” (life force) which strives to feed and grow, while the semen carries a “vital heat” or spirit which provides the initial spark or movement to generate the new life, and provides the “sensitive soul” element,  meaning the potentiality for the development of the senses.

Aristotle’s guiding mantra is “Nature makes nothing in vain”, which to me is the reverse side of the same coin – as Darwin might have said –  “Nature allows nothing to continue in vain” (with the exception of the human appendix!)

Favourite lines/passages:  On the mating of hedgehogs ….

“… their union must be quick, for the hedgehog does not …. mount upon the back of the female, but they conjugate standing upright because of their spines”          page 257

(OK I checked this on YouTube and its not always true – they do mate as other mammals, and not that quickly either. Love – or at least sex – knows no limits!)

and a nice summation of the entire series of biological lectures:

“it is impossible .. to be eternal as an individual …. but it is possible for it as a species”  page 272

Personal rating:  Only a 3. I grew tired of this by halfway and admit I skimmed the second half rather brutally.  Inevitably some of Aristotle’s theories are built on conjectures, and building one conjecture on top of another creates a sense of disinterest in the whole exercise. And probably some 21st century arrogance as well. 🙂

The sanity in between: I have badly hurt my foot somehow and been spending a lot of time resting. Oddly I haven’t done much reading of the classics with all this enforced rest, but spent quite a lot of time browsing my collection of walking guides for long distance paths in Britain – some irony there somewhere I’m sure.

Next : Now that the zoology is finished, where to next?  WIth only four days of March remaining, perhaps a change of pace and have a stab at Aristotle’s Nicomachean Ethics?


114. On the Gait of Animals (De Incessu Animalium), and, On the Motion of Animals (De Motu Animalium) by Aristotle (c.350 BC)

114. On the Gait of Animals (De Incessu Animalium), and, On the Motion of Animals (De Motu Animalium) by Aristotle (c.350 BC)

Plot:   Two short lectures connected by the idea of movement in animals. On the Gait of Animals discusses the various types of movement of animals and their different arrangements of limbs, whereas On the Motion of Animals is more concerned with the physics underlying the movement.

My copy is still from the 2 volumes of the works of Aristotle which form part of the series Great Books of the Western World, published by Encyclopaedia Britannica in 1952.

My thoughts:  

On the Gait of Animals is in the same vein as the preceding On the Parts of Animals, describing and investigating the anatomy of the limbs of animals, and asks such obvious questions that are so elementary yet taken for granted – the sort of thing a young child might ask a parent – why do most animals have four legs? why don’t some animals have odd numbers of legs?, and also questions few people at all would consider : why does man have arms that flex inward when most animals have forelegs that flex outward?

Aristotle also seemed fascinated with the crab – the only animal that moves sidewards. I would have loved to see what he thought of kangaroos, although he was certainly familiar with other animals that jump.

On the Motion of Animals  is more concerned with the physics of movement, such as the need for a fixed solid substrate for the animal to push against when moving, but also the driving forces of movement : desire and intellect which motivate the animal to set itself in motion.

“the living creature is moved by intellect, imagination, purpose, wish and appetite. And all these are reducible to mind and desire.”

Personal rating:  Not as easy a read as you would suppose from the above. Aren’t you glad I break it down into simplicities even I can understand 🙂  I think I can only give these a 3.

The sanity in between:   A new spot on each post, so you can see what non-classic/s I also read since last post.  In between Aristotle’s biological treatises, I read The Dragon Reborn (volume 3 of the Wheel of Time fantasy series) by Robert Jordan, and Love among the Chickens by the great P. G. Wodehouse. Definitely an animal theme this month.

Next :  Finishing off the zoology with Aristotle’s Generation of Animals.


113. De partibus animalium (On the parts of animals) by Aristotle (c.350 BC)

113. De partibus animalium (On the parts of animals) by Aristotle (c.350 BC)

Plot: Not as all encompassing as Historia animalium, this work examines the internal composition of the parts of animals on three levels – the elemental, the homogenous and the heterogeneous, so perhaps the first writings devoted to histology – the study of the cells, tissues and organs of the body.

My copy is from the 2 volumes of the works of Aristotle which form part of the series Great Books of the Western World, published by Encyclopaedia Britannica in 1952.

My thoughts: A more turgid read than the previous works on zoology by Aristotle. The three levels of composition start with the elemental, preserving the concept of earth, fire and air and water as the base constituents of cells. The next higher levels divides organs and tissues into homogenous (all made from the same material) which includes flesh, blood, and most internal organs, and heterogeneous (the eyes, hands, face) made from a variety of materials.

Aristotle can see the overall picture of the skeletal, circulatory and digestive systems, although he only recognises blood as delivering nutrients through the body but not the need for oxygen transport. The heart is the seat of all sensation, with the various senses reporting directly to it. The brain is only a cooling mechanism to stop overheating of the blood, as is the breathing in of air by the lungs.

The various adaptations observed in animals (different beak shapes in birds, presence of tusks/horns in some animals, etc.) are given to them by Nature depending on what the animal needs and can use best – a topsy-turvy way of looking at the evolution of traits. In passing it is interesting that no divine presence is named other than Nature, and yet she is routinely named as the active agent in assigning such characteristics to each species, and I am unclear if Aristotle is using this name in a direct or indirect sense.

Favourite lines/passages:

The ideal start to any book on zoology, pulled from the last chapter of book 1, and worth the price of admission alone:

“Having already treated of the celestial world, as far as our conjectures should reach, we proceed to treat of animals, without omitting, to the best of our ability, any member of the kingdom, however ignoble. For if some have no graces to charm the sense, yet even these, by disclosing to intellectual perception the artistic spirit that designed them, give immense pleasure to all who can trace links of causation and are inclined to philosophy …..  we therefore must not recoil with childish aversion from the examination of the humbler animals : every realm of nature is marvelous …. so we should venture on the study of every kind of animal without distaste; for each and all will reveal to us something natural and something beautiful”                                                                              page 168-169

and for sheer fun, something to ponder

“Nature, who makes nothing in vain, has given no eyelids to fishes”                 page 184

Personal rating: Saved from a 2 by the two above quotes. 3.

Next :  Continuing with Aristotle’s biological treatises, On the motion of animals (De motu animalium)

112. Historia animalium by Aristotle (c.350 BC)

112. Historia animalium by Aristotle (c.350 BC)

Plot:    A very detailed and thorough textbook of zoology from the 4th century BC. I must confess to reading the first two-thirds but only skimming the last third, but enough to get the gist and write this post.

My copy is from the 2 volumes of the works of Aristotle which form part of the series Great Books of the Western World, published by Encyclopaedia Britannica in 1952.

My thoughts: Aristotle must have taken a long time to research and write this work, and it is interesting to see the range of species he had access to for observation and dissection from his base in Greece : elephants, lions, seals, dolphins, bears, bison (the European species obviously), hippopotamus, monkeys, swordfish, crocodiles, sea snakes and chameleons to name the most frequently mentioned just in the opening pages. He also includes the many of the major groups of invertebrates.

I cannot fault the majority of his comments on anatomy – he obviously took great care in his studies, and it seems churlish to mention the occasional mistake amongst such a wealth of knowledge and effort. As he progresses onto more behavioural considerations, more errors arise but generally I was impressed with how much he got right rather than the clangers – he even teeters on the idea of genetics, as he muses on an infinitesimally small organ which can make enormous changes to the animal. He also ventures into theories of biogeography, and ecological strategies such as competition, migration and hibernation, and specific diseases of various species.

“The elephant, which is reputed to enjoy immunity from all other illnesses, is occasionally subject to flatulence”   Page 130.

For the modern reader who isn’t fascinated with the accuracy of ancient biological study, the intriguing bits are when Aristotle is completely wrong : the inclusion of the mythical beast  the man-eating martichoras (manticore) with the body and legs of a lion, the face of a man with three rows of teeth, and a scorpion tail that can shoot spines like arrows (although in fairness, Aristotle does admit this description is from Ctesias, a Greek physician living in Persia, and hinting that this creature may not be correctly described); or how some creatures are spontaneously generated from leaf litter, slime or dung, fire or snow or rainwater,  and not the result of sexual reproduction : the hermit-crab, the eel, various grubs, worms and parasites.  And as for nursing human mothers giving forth milk from their armpits as well as their breasts ….????

I also enjoyed his attempts to classify the vast variety of species into some sort of order, largely on their number of limbs and method of giving birth, but succeeding in recognising mammals (although not named as such), birds, fishes,  insects, molluscs, crustaceans, etc.

He also seems to waver between chapters in his opinion on whether dolphins and other cetaceans are fish or not, and whether grubs or maggots give rise to adult insects or not, which may lead credence to some belief that part of this was written by other teachers or students at Aristotle’s academy.

Favourite lines/passages:

“The hyaena … will lie in wait for a man and chase him, and inveigle a dog within its reach by making a noise that resembles the retching noise of a man vomiting. It is exceedingly fond of putrefied flesh, and will burrow in a graveyard to gratify this propensity.”    Page 120

“Serpents have an insatiate appetite for wine …. men hunt for snakes by pouring wine into saucers … and the creatures are caught when inebriated”       Page 120

“The weasel has a clever way of getting the better of birds, it tears their throats open”   page 138


More new words …

Frangible: able to broken into fragments

Wind-eggs : unfertilised birds’ eggs

Personal rating: More read as a curiosity than enjoyment or education, I will give it a 4.
Kimmy’s rating: 
Dissection in general does not sit well with Kimmy so she politely declines to comment. 

Next :  De partibus animalium (On the parts of animals) – more zoology by Aristotle.


111. Parva Naturalia by Aristotle (c. 350 BC)

111. Parva Naturalia by Aristotle (c. 350 BC)

Plot: These are seven short treatises on biological phenomena, directly flowing on from the lecture De Anima (On the Soul) by Aristotle. I will discuss my thoughts on each one separately below, so get comfy because this might take some time.

My copy is from the 2 volumes of the works of Aristotle which form part of the series Great Books of the Western World, published by Encyclopaedia Britannica in 1952.

My thoughts:

i) On Sense and Sensibilia

Not Jane Austen’s excellent novel unfortunately.

This picks up straight after On the Soul, and was a little easier to follow, either from having some of the ideas about the sense organs and senses already covered or perhaps a more sympatico editor/translator (J. I. Beare in this case)

Points worth sharing include:

  • Colours are a mixture of particles of black and white, sometimes in specific ratios. Likewise, flavours are combinations of sweet and bitter in different ratios. (Aristotle likes his maths!)
  • There are 2 distinct types of odours : those related to nutrition where an animal can identify what is good or bad to eat and locate it, and those related to pleasure which only humans appreciate, and once inhaled rise up to the brain where they promote health.
  • Flavours range from sweet, which directly provide nourishment, to salty, acid and bitter which act as seasoning

ii) On Memory

  • Only animals which perceive time can have memory
  • Memories are sensory imprints, and weakest in the very young and very old as their receiving organs do not imprint due to their bodies’ rapid state of growth or decay.
  • Remembering is not the same as recollection : the latter requires active effort and searching to reach the required memory.  Connection of memories allows recollection more easily.

Digression #1.  I can still remember a UK comic I read as a child (I’m sure it was in an issue of Whizzer and Chips) where the sport-mad boy was in an exam that he hadn’t studied for. The next panel showed a view inside his brain of this enormous pile of tiny pieces of paper, each with some obscure fact written on it (“Don’t eat peanut butter after cleaning your teeth”, etc.) and two little men sifting through it all one by one to find the answer to the question. It remains my favourite image of the human memory at work.

iii) On Sleep

  • Since sleep is the resting of organs of sense-perception, then it follows that plants do not sleep or dream (shame : I love the idea of dreaming trees!)
  • Since all sense organs rest simultaneously during sleep, they must be controlled by a central primary organ, which must be the heart
  • Because heat from the food eaten rises to the head, making it heavy ; then you will feel tired after a big meal. Logical.

Digression #2. Does anyone else, when reading novels, decide to call it a night when the characters in the story go to sleep? Almost as if you can be assured they won’t go off and continue their adventures while you sleep. Or should I book into a good psychiatrist?

iv) On Dreams

  • Perceptions from sense organs during waking time have a momentum or afterimage which gets distorted from the heat travelling in the body.
  • The eye can cause an effect on things it sees as well as receive an image. Hence, a woman having her period can cause a highly polished or new mirror to develop a blood-coloured haze (Aristotle had rejected belief in reciprocal effects on objects caused by the sense organs in his earlier work On the Soul,so how he came to state this is disappointing)

v) On Divination in Sleep

Aristotle is undecided on believing in the ability to tell the future via dreams. He admits that many people have reported such instances, but dismisses most as coincidence. He also thinks that most people who claim such prophetic dreams are unlikely to be sent messages from God as they are base commoners and so too ignorant and unimportant to be chosen.

vi) On Length and Shortness of Life

Some animals live longer than others, just as some plants live longer. The secret is the amount of humidity and warmth in their bodies. As the humidity cools and congeals, or dries up, we age and die. Larger organisms tend to live longer as they have a larger quantity of this humidity. Plants have a oiliness or viscosity to their liquid which resists these changes, but they also renew parts of themselves by growing new shoots and roots.

vii) On Youth, Old Age, Life and Death, and Respiration

  • Some animals continue to live and move after parts like the head are removed as they still have the soul attached via the dominant organ with supreme control of the sensory and digestive functions – the heart (although others thought it was the brain).

More is made of the gradual dissipation of the body’s fire with age until death ensues in a natural way. There was also a lot of talk of the need for a certain degree of cooling of the body during life, presumably to stop all the fire from escaping too quickly, but the logic here escapes me.


Aristotle was no doubt a brilliant observer of many things, even if his conclusions were not always spot on – shame he didn’t develop the Scientific Method. But in the spirit of Herodotus as Father of History, I think Aristotle merits the title of the Father of Science.

More diversions and digressions:  Some unfamiliar words turned up while reading these lectures. How many do you know?

sapidity : flavour

sanguineous :  resembling or containing blood

gustable :  a thing which can be tasted

deglutition:  act of swallowing

desiderative:  something someone wants to do (a little vague, sorry 🙂  )

murex: sea snails, used by the Ancient Phonecians to make purple dyes

atrabilious : melancholy or (probably more likely) irritable, related to an excess of bile perhaps?

Try using two or more in a sentence today (extra points for sounding either Wodehousian or Dickensian) ….

“Ah, these murex have a sapidity which is quite likely to make me atrabilious”

“Then you should refrain from deglutition, old bean!”

Personal rating: Better than De Anima, but still a struggle to understand some parts. Only  a 3.

Next :  More Aristotle. Historia animalium (History of animals)