Ancient peoples wondered where flies came from, where algae came from, where mold came from, where frogs came from, etc.  Those who read the Bible found passages such as these:


Gen 1

11 And he said: Let the earth bring forth the green herb, and such as may seed, and the fruit tree yielding fruit after its kind, which may have seed in itself upon the earth. And it was so done.

12 And the earth brought forth the green herb, and such as yieldeth seed according to its kind, and the tree that beareth fruit having seed each one according to its kind. And God saw that it was good.

11   And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it

was so.

12   And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it

was good.


20 God also said: Let the waters bring forth the creeping creature having life, and the fowl that may fly over the earth under the firmament of heaven.

21 And God created the great whales, and every living and moving creature, which the waters brought forth, according to their kinds, and every winged fowl according to its kind. And God saw that it was good.

20   And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven.

21   And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his

kind: and God saw that it was good.


24 And God said: Let the earth bring forth the living creature in its kind, cattle and creeping things, and beasts of the earth, according to their kinds. And it was so done.

25 And God made the beasts of the earth according to their kinds, and cattle, and every thing that creepeth on the earth after its kind. And God saw that it was good.

24   And God said, Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind: and it was so.

25   And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it

was good.


Gen 2

19 And the Lord God having formed out of the ground all the beasts of the earth, and all the fowls of the air, brought them to Adam to see what he would call them: for whatsoever Adam called any living creature the same is its name.

19   And out of the ground the LORD God formed every beast of the field, and every fowl of the air; and brought them unto Adam to see what he would call them:

and whatsoever Adam called every living creature, that was the name thereof.


Ex 7

10 So Moses and Aaron went in unto Pharao, and did as the Lord had commanded. And Aaron took the rod before Pharao, and his servants, and it was turned into a serpent.

11 And Pharao called the wise men and the magicians: and they also by Egyptian enchantments and certain secrets did in like manner.

10   And Moses and Aaron went in unto Pharaoh, and they did so as the LORD had commanded: and Aaron cast down his rod before Pharaoh, and before his

servants, and it became a serpent.

11   Then Pharaoh also called the wise men and the sorcerers: now the magicians of Egypt, they also did in like manner with their enchantments.


Ex 8

6 And Aaron stretched forth his hand upon the waters of Egypt, and the frogs came up, and covered the land of Egypt.

7 And the magicians also by their enchantments did in like manner, and the brought forth frogs upon all the land of Egypt

6   And Aaron stretched out his hand over the waters of Egypt; and the frogs came up, and covered the land of Egypt.

7   And the magicians did so with their enchantments, and brought up frogs upon the land of Egypt.


Ex. 8

16 And the Lord said to Moses: Say to Aaron, Stretch forth thy rod, and strike the dust of the earth: and may there be sciniphs in all the land of Egypt.

17 And they did so. And Aaron stretched forth his hand, holding the rod: and he struck the dust of the earth, and there came sciniphs on men and on beasts: all the dust of the earth was turned into sciniphs through all the land of Egypt.

16   And the LORD said unto Moses, Say unto Aaron, Stretch out thy rod, and smite the dust of the land, that it may become lice throughout all the land of Egypt.

17   And they did so; for Aaron stretched out his hand with his rod, and smote the dust of the earth, and it became lice in man, and in beast; all the dust of the land

became lice throughout all the land of Egypt.


      In these passages, plants are generated from earth, birds and fish from water (although in Gen. 2 birds are generated from earth, differing from the version in Gen. 1), beasts from earth, frogs from the waters of the Nile, lice from dust, etc.    Some people took these passages literally and believed that spontaneous generation was the normal mode of reproduction for many forms of life.



Saint Augustine felt that animals that were produced through spontaneous generation were not necessarily included on Noah’s Ark, thus making the task of collecting all living things less formidable.

As to another customary inquiry of the scrupulous about the very minute creatures, not only such as mice and lizards, but also locusts, beetles, flies, fleas, and so forth, whether there were not in the ark a larger number of them was determined by God in His command, those persons who are moved by this difficulty are to be reminded that the words “every creeping thing of the earth” only indicate that it was not needful to preserve in the ark the animals that can live in the water, whether fishes that live submerged in it, or the sea birds that swim on its surface.  Then, when it is said “male and female”, no doubt reference is made to the repairing of the races and consequently there was no need for those creatures being in the ark which are born without the union of the sexes from inanimate things, or from their corruption; or if they were in the ark, they might be there as they commonly are in houses, not in any determinate numbers; or if it was necessary that there should be a definite number of all those animals that cannot naturally live in the water, that so  the most sacred mystery which was being enacted might be bodied forth and perfectly figured in actual realities, still this was not the care of Noah or his sons, but of God.  For Noah did not catch the animals and put them into the ark, but gave them entrance when they came seeking it.  For this is the force of the words “They shall come unto thee”—not that is to say, by man’s effort, but by God’s will.  But certainly we are not required to believe that those which have no sex also came; for it is expressly and definitely said “They shall be male and female.”  For there are some animals  which are born out of corruption, but yet afterwards they themselves copulate and have produce offspring, as flies; but others, which have no sex, like bees….

Saint Augustine, City of God, Book XV.27


Saint Augustine was at a loss to explain how the living things which had been saved from the Noachian Flood could have traveled to distant lands.  He felt that perhaps angels were needed for transport (and, to use modern examples, this would explain how koalas reached Australia, sloths reached South America, desert tortoises reached the American Southwest, etc.).  This daunting task was easier if many animals could simply develop from the earth of various continents and islands.

There is a question raised about all those kinds of beasts which are not domesticated, nor are produced like frogs from the earth, but are propagated by male and female parents such as wolves and animals of that kind; and it is asked how they could be found in the islands after the deluge, in which all the animals not in the ark perished, unless the breed was restored from those which were preserved in pairs in the ark.  It might, indeed, be said that they crossed to the islands by swimming, there are some so distant, that we fancy no animal could swim to them.  But if men caught them and took them across with themselves, and thus propagated these breeds in their new abodes, this would not imply an incredible fondness for the chase.  At the same time, it cannot be denied that by the intervention of angels they might be transferred by God’s order or permission.  If, however, they were produced out of the earth as at their first creation, when God said, “Let the earth bring for the living creature”, this makes it more evident that all kinds of animals were preserved in the ark, not so much for the sake of renewing the stock, as of prefiguring the various nations which were to be saved in the church; this I say, is more evident, if the earth brought forth many animals in islands to which they could not cross over.

-- Saint Augustine, City of God , Book XVI. 7


23. But whether, as I have said, we are to believe that these little animals were also made in the creation of things during the six days of the Scripture narrative, or afterwards at the decomposition of corruptible bodies, that is the question. Surely it can be said that the smallest of these animals that have their origin in the waters and the earth were made at the first creation.     Among these it is not unreasonable to place those that come forth from the creatures born with the budding earth. For these creatures preceded the creation not only of the animals but     also of the luminaries of heaven, and, being rooted in the earth     from which they came forth on the day on which the dry land     appeared, obviously they are rather to be reckoned as an adjunct     of the inhabitable earth than numbered among its inhabitants.        As for the other small creatures that come forth from the bodies of animals, particularly from corpses, it is absurd to say that     they were created when the animals themselves were created,     except in the sense that there was present from the beginning     in all living bodies a natural power, and, I might say, there were     interwoven with these bodies the seminal principles of animals     later to appear which would spring forth from the decomposing bodies, each according to its kind and with its special properties, by the wonderful power of the immutable Creator who     moves all His creatures.

--Saint Augustine, The Literal Meaning of Genesis, Vol. 1., Book 3, Section 23


In so far as our powers of observation and our human intelligence can understand nature, we have no evidence that any flesh with life and sensation is born unless it is from one of four sources: either from water and earth, which serve as material elements, or from the shoots or the fruits of trees, or from the flesh of animals (as happens in the case of countless kinds of worms and reptiles), or from the copulation of parents.

--Saint Augustine, The Literal Meaning of Genesis, Vol. 2., Book 9, Section 29


St. Thomas Aquinas felt that “imperfect animals” can come to be through spontaneous generation, especially through decomposing matter.  Matter either has the power to generate life due to an original power given to the elements or to the influence of the stars.  For imperfect animals, the influence of heavenly bodies alone suffices and it is through this power that angels and demons can influence the production of living things.


St. Thomas Aquinas; Summa Theologica, Book I

Q. 45

Obj. 3.  Further, in nature, like begets like.  But some things are found generated in nature by a thing unlike to them; as is evident in animals generated through putrefaction.  Therefore their form is not from nature, but by creation..

Reply Obj. 3.  For the generation of imperfect animals, a universal agent suffices, and this is to be found in the celestial power to which they are assimilated, not in species, but according to a kind of analogy.  Nor is it necessary to say that their forms are created by a separate agent. 


St. Thomas Aquinas; Summa Theologica, Book I

5th day

Q.      71

Obj. 1.  It would seem that this work is not fittingly described.  For the waters produce that which the power of water suffices to produce.  But the power of water does not suffice for the production of every kind of fishes and birds, since we find that many of them are generated from seed.  Therefore the words, Let the waters bring forth the creeping creatures having life, and the fowl that may fly over the earth, do not fittingly describe this work.

Obj. 3.  Further, fishes move in the waters and birds in the air.  If then, fishes are produced from the waters, birds ought to be produced from the air, not from the waters.

Reply Obj. 1.  It was laid down by Avicenna that animals of all kinds can be generated by various minglings of the elements and, even naturally, without any kind of seed.  This however, seems repugnant to the fact that nature produces its effects by determinate means; and consequently, those things that are naturally generated from seed cannot be generated naturally in any other way.  It ought, then, rather to be said that in the natural generation of all animals that are generated from seed, the active  principle lies in the formative power of the seed, but that in the case of animals generated from putrefaction, the formative power is the influence of the heavenly bodies…Not as though water or earth has in itself the power of producing all animals, as Avicenna held, rather it is from the power originally placed in the elements that they are able to produce animals either from elemental matter by the power of seed or the influence of the stars.

Reply Obj. 3.   …But birds move in the lower part of the air, and so are said to fly beneath the firmament, even if the firmament be taken to mean the region of the clouds.  Hence the production of birds is ascribed to the water.


St. Thomas Aquinas; Summa Theologica, Book I

Q.      91, 2nd Art

Reply Obj. 2.  Perfect animals, prodcued by seed, cannot be made by the sole power of a heavenly body, as Avicenna imagined, although the power of a heavenly body may assist by co-operation in the work of natural generation, for as the Philosopher says, man and the sun beget man from matter.  For this reason, a place of moderate temperature is required for the production of man and other perfect animals.  But the power of the heavenly bodies suffices for the production of some imperfect animals from properly disposed matter; for it is clear that more conditions are required to produce a perfect than an imperfect thing.


St. Thomas Aquinas; Summa Theologica, Book I

Q 105, 2nd Art.

Reply Obj. 1: Thus animals, produced by putrefaction, and plants and minerals are like the sun and stars, by whose power they are produced.

Hence angels and demons act on visible matter, not by imprinting forms in matter, but by making use of corporeal seminal principles.


Luther felt that mice could spontaneously arise from decaying matter.

Here questions are raised also about the mice and door mice, whence they originate and how.  Indeed, we have learned from experience that not even ships which are continually floating on the sea are safe from mice.  Likewise, no house can be so thoroughly cleaned that no mice are produced in it.  We can also inquire about the manner in which flies come into existence.  Likewise, where the birds go in the fall….Thus mice belong to the kind produced by their unlike, because mice originate not from mice alone but also from decay, which is used up gradually and gradually turns into a mouse….The sun warms; but it would bring nothing into being unless God said by His divine power:  “Let a mouse come out of the decay.”  Therefore the mouse too, is a divine creature, and, in my judgement, of a watery nature and, as it were, a land bird;  otherwise it would have the form of a monster, and its kind would not  be preserved.  But for its kind it has a very beautiful form—such pretty feet and such delicate hair plain in view.  Therefore here, too, we admire God’s creation and workmanship.  The same thing may be said about flies.

     About birds I surely have no knowledge.  It is not likely that they go to regions lying more toward the south, inasmuch as from experience it has been learned that the swallows lie dead in the waters throughout the winger and return to life at springtime.  This is truly a weighty proof of our resurrection.  Therefore I think that birds are preserved either in trees or in waters.  These works of the Divine Majesty are plainly miraculous.  So we see them, and yet we do not understand them. 

Martin Luther, Commentaries on Genesis, Vol. 1, p. 52


Calvin argued that fish are still produced from water as simply a continuation of the miracle which occurred at the creation of the world.

21 When he says that "the waters brought forth," he proceeds to commend the efficacy of the word, which the waters hear so promptly, that, though lifeless in themselves, they suddenly teem with a living offspring, yet the language of Moses expresses more; namely, that fishes innumerable are daily produced from the waters, because that word of God, by which he once commanded it, is continually in force.

--Calvin, Commentary on Genesis, Ch. 1. 21


St. Basil included mice, eels, frogs, and insects with those animals which arise through spontaneous generation.  St. Isidore and Abraham Milius held similar beliefs about insects, fish, and birds.

 For, if there are creatures which are successively produced by their predecessors, there are others that even to-day we see born from the earth itself. In wet weather she brings forth grasshoppers and an immense number of insects which fly in the air and have no names because they are so small; she also produces mice and frogs. In the environs of Thebes in Egypt, after abundant rain in hot weather, the country is covered with field mice.  We see mud alone produce eels; they do not proceed from an egg, nor in any other manner; it is the earth alone which gives them birth.  Let the earth produce a living creature."

--Saint Basil Homily IX.2


St. Isidore “bees are generated from decomposed veal, beetles from horseflesh, grasshoppers from mules, scorpions from crabs”

--White, p. 55


Many felt that animals might be generated through witchcraft.

There is war and deathless hatred between the wicked Demon and Nature; for whereas every effort of Nature is directed upon procreation and production, the Demon always strives to spoil and destroy her works.  And as if he were not content with hail and snow and other destructive phenomena of the weather, in which he is popularly believed to bear a hand, he ceases not to use many other astonishing means to compass his purpose.  Alexia Violaea bore witness that, after running here and there with he companions, she used to scatter in the air a fine powder given to her by the Demon for that purpose; and that from this were generated caterpillars, bruchuses, locusts, and such pests of the crops in such numbers that the fields on all sides were at once covered with them.  Ervette Hoselette said that by a similar method they had more  than once raised a great army of mice which at once burrowed into the ground and gnawed at the roots fo the growing crops.  Jeanne Porelle confessed that if she bore a grudge against anyone she used to send the breeze upon his cattle so that they died a slow and miserable death through its continual stinging…I suspect also that, when showers of frogs fall with the rain during a thunderstorm, it is by the Demon’s art that they have first been raised into the air…

Remy, 1595, p. 67


The idea of spontaneous generation continued for centuries.

1667  Abraham Milius “the earth and the waters, and especially the heat of the sun of the genial sky, together with that slimy and putrid quality which seems to be inherent in the soil, may furnish the origin for fishes, terrestrial animals, and birds.”

--White, p. 46


But what our eyes have seene; and hands touched we shall declare.  There is a small Island in Lancashire…whereon is found a certain spume of froth that in time breedith unto certain shells, in shape like those of the Muskle, but sharper pointed, and of whitish colour, one end whereof is fastened unto the inside of the shell, even as the fish of Oisters and Muskels are; the other end is made fast unto the belly of a rude masse or lumpe which in time commeth to the shape of a Bird; when it is perfectly formed the whell gapeth open, and the first thing that appeareth is the foreseaid lace or string; next it openeth the shell by degrees, til at length it is all come forth and hangeth onely by the bill:  in short space after it cometh forth to full maturitie and falleth unto the sea, where it gathereth feathers, and groweth to a fowle bigger than a Mallard…They spawn as it were in March and April; the geese are formed in May and June, and come to fulnesse of feathers the month after.  And thus having through God’s assistance…we conclude and end our present Volume with this Wonder of England.  For the which God’s Name be ever honoured and praised.

Gerrards’ Herbal 1594, from Hogben, 1930, p.   134-5


Concerning the generation of frogs we shall briefly deliver that account which observation hathe taught us.  By frogs I understand not such, as arising from putrefaction are bred without copulation and because they subsist not long are called temporariae

mid-17th century Thomas Browne, from Hogben, 1930, p.   135


So may one doubt whether in cheese and timber worms are generated; or if beetles and wasps in cow’s dung; or if butterflies, locusts, grasshoppers, shell fish, snails, eels, and such like be procreated of putrefied matter which is apt to receive the form of that creature to which it is by formative powers disposed.  To question this is to question reason, sense, and experience.  If he doubt of this let him go to Egypt and there he will find the fields swarming with mice, begot of the mud of Nylus, to the great calamity of the inhabitants.

Alexander Ross, from Hogben, 1930, p. 136


…the theory of spontaneous generation was held by many, perhaps by all the Fathers of the Church and that St. Thomas Aquinas himself when rebuking Avicenna for teaching spontaneous generation did so because Avicenna held the thesis that it was by the power of matter alone that life arose, whereas, as St. Thomas says, if matter does produce life it is because the Creator has given it the power to do so.

Windle, 1908, p. 84


Harvey was by no means opposed to spontaneous generation; which on the contrary he adopted for worms, insects, etc.

Driesh, 1914, p. 26


Further considerations concerning spontaneous generation of infusoria and worms from decomposed elements…lead Tiedemann—not very logically—to postulate the existence of a “vital matter”…

Driesh, 1914, p. 108


Cotton Mather, rather than use the Bible to support the idea of spontaneous generation, referred to observations of the natural world to refute it.

Dr. Gorden adds to the assurances which all the inquisitive before him have given us, that no insects are bred of corruption, but all ex ovo. [from eggs]

Cotton Mather, The Christian Philosopher, 1721, p. 144


Concerning frogs generated in the clouds, there has been a mighty noise; the thunder scarce makes a greater!  But Mr. Ray says well, it seems no more likely than Spanish gennets begotten by their wind.  He adds, “He that can swallow the raining of frogs, hath made a fair step towards believing that it may rain calves also; for we read that one fell out of the clouds in Avicen’s time.”  Fromondus’ opinion, that the frogs which appear in great multitudes after a shower, are not indeed generated in the clouds, by are coagulated of dust, commixed and fermented with rain-water, is all over as impertinent.  It is very certain that frogs are of two different sexes…and the eggs lie in the midst of a copious jelly…

Cotton Mather, The Christian Philosopher, 1721, p. 146


    Some who believed in spontaneous generation reconciled this belief by interpreting the Genesis account of the creation of life to include a life-giving force in matter.  Thus, all life which would later develop from that latter had a preexistence which could be dated back to creation.

Preexistence theories  first appeared as an attempt to explain so-called spontaneous generation, and only after the appearance of ovist and spermist preformationist ideas did it become the explanation of all generation.  Bothe Daniel Sennert and Pierre Gassendi held to such preexistent theories in their dealings with spontaneous generation.  The former held to preexistent souls. The latter to preexisting germs.  On the one hand, Sennert, an early anatomist, believed the atoms alone were incapable of rearranging themselves to form a living being; they must be animated by a soul.  Since a soul cannot be produced from matter, only from God, and since God had ceased to create, there must be an uninterrupted chain of souls running back to the first creation of each species.  Thus spontaneous generation can only occur in matter endowed with a soul, that is, in living matter or matter that was once alive.

Farley, p. 12


Before the life cycle of parasitic worms was understood, it was believed that they generated spontaneously in human intestines.  This belief was reconciled with the Genesis account of creation by stating that Adam not only had the seeds of all future humanity in him, but also the seeds of all future worms.

The problem of wastage that accrues if the worm seeds enter with food and water—or even through the skin as Andry believed—could however, be solved from another point of entry.  The worm seeds could be assumed to pass directly from host to offspring during copulation, lactation, or across the placental barrier.  “Why might not one say, that in case the seed of the worm did not enter the patient’s body along with the vituals, perhaps it might have accompanied the blood of his father from the time of his conception…May we not rather conceive that these very same seeds were created in the seed of man, along with man himself.”

…This theory, in which poor Adam not only contained all of mankind-to-be but also all his worms-to-be…

Vallisneri attempted to extricate the theory from this dilemma by assuming that the worms did good works before the Fall.

Adam could support and feed those insects which had a mind to live together quietly and friendly, as we may say; and if anything superfluous remained, that they might eat…and not transgress their bounds or eat holes through the sides of the guts…But this happiness of Adam was but of short continuance, for disobeying God…all things were suddenly changed…

(quotes from early 1700s) from Farley, p.  20-1


The idea of spontaneous generation continued to receive support from some religious individuals in Darwin’s day and from vitalists.


When Charles Darwin was writing The Origin of Species by Means of Natural Selection, the possibility of “spontaneous generation” was still a very controversial question….Many observers were convinced not only by what they saw, but also by the fact that God had commanded, “Let the waters bring forth living creatures,” a command which they considered had never been rescinded.

--Hearn, Walter from Mixter, p. 53


Louis Pasteur rendered a great service to biology and medicine in his experiments showing that spontaneous generation is a concept without foundation in fact—a serious setback for mechanism as well as for those hyper-viatlists who believed God creates maggots in rotting meat and tadpoles in water.

-- Key, Thomas from Mixter, p. 14


Modern creationists argue that the idea that life could have arisen in the early earth over millions of years of chemical reactions in oceans filled with organic molecules is not only false, but an argument which opposes the Bible.  It is interesting to note therefore, that throughout most of the history of Christianity, Christians have believed that spontaneous generation was not only possible but common.  The believers of spontaneous generation include many of the great theologians of the past and Bible passages were sometimes employed to support these views.