Did Christians actually debate how many angels can dance on the head of a pin?
Historically it seems to have possibly been debated, for whatever reason!!! This is a reductio ad absurdum challenge to medieval scholasticism in general, and its angelology in particular, as represented by figures such as Duns Scotus and Thomas Aquinas.
In modern usage, the term has lost its theological context and is used as a metaphor for wasting time debating topics of no practical value, or questions whose answers hold no intellectual consequence, while more urgent concerns accumulate.
Thomas Aquinas's Summa Theologica, written c. 1270, includes discussion of several questions regarding angels such as, "Can several angels be in the same place?" However, the idea that such questions had a prominent place in medieval scholarship has been debated, and it has not been proved that this particular question was ever disputed. One theory is that it is an early modern fabrication, used to discredit scholastic philosophy at a time when it still played a significant role in university education. James Franklin has raised the scholarly issue, and mentions that there is a 17th-century reference in William Chillingworth's Religion of Protestants (1637), where he accuses unnamed scholastics of debating "whether a Million of Angels may not fit upon a Needle's point?" This is earlier than a reference in the 1678 The True Intellectual System Of The Universe by Ralph Cudworth. Helen S. Lang, author of Aristotle's Physics and its Medieval Varieties (1992), says (p. 284):
The question of how many angels can dance on the point of a needle, or the head of a pin, is often attributed to 'late medieval writers'.... In point of fact, the question has never been found in this form…
Peter Harrison (2016) has suggested that the first reference to angels dancing on a needle's point occurs in an expository work by the English divine (minister), William Sclater (1575–1626). In An exposition with notes upon the first Epistle to the Thessalonians (1619), Sclater claimed that scholastic philosophers occupied themselves with such pointless questions as whether angels "did occupie a place; and so, whether many might be in one place at one time; and how many might sit on a Needles point; and six hundred such like needles points."bHarrison proposes that the reason an English writer first introduced the "needle’s point" into a critique of medieval angelology is that it makes for a pun on "needless point".
A letter written to The Times in 1975 identified a close parallel in a 14th-century mystical text, the Swester Katrei. However, the reference is to souls sitting on a needle: tusent selen siczen in dem himelrich uff einer nadel spicz — "in heaven a thousand souls can sit on the point of a needle."
Other possibilities are that it is a surviving parody or self-parody, or a training topic in debating.
In Italian, French, Spanish and Portuguese, the conundrum of useless scholarly debates is linked to a similar question of whether angels are sexless or have a sex. - How many angels can dance on the head of a pin?
The question has become one not only of a metaphor for wasting time, but also a symbol and pointless sophistry of medieval scholastics. Who debates what is a waste of time?
This question became a symbol for the silly and pointless sophistry of medieval scholastics. But as modern scholarship has shown scholastics was not such a thoughtless desert as some of its caricatures: the role of Duns Scotus and Ockham in the development of epistemology and modal logic is well known, as is the influence of Buridan and Oresme on science and philosophy of Descartes and Galileo, the problem of universals is still actively discussed. Still I was surprised to read this in Butterfield-Isham's paper (p.46) on modern physics:
"This situation inevitably prompts the sceptical question why we are spending time and effort discussing possible philosophical implications of an equation [the Wheeler-DeWitt equation in quantum gravity] that is mathematically meaningless! Are we as misguided as the medieval scholastics are often taken to have been, in their discussions of how many angels can dance on the head of a pin? We believe not. Indeed, as philosophers know well, the scholastics’ discussions were not as misdirected as folklore suggests. They addressed deep, maybe perennial, issues about personal identity and spatiotemporal location, in terms of their era’s accepted ontology; which included angels". How many angels can dance on the head of a pin?
If fact St. Thomas Aquinas argues something akin to this in his Summa Theologica I q. 52 a. 3 ("Whether several angels can be at the same time in the same place?")
Aquinas argues in Summa Theologica I q. 52 a. 3 ("Whether several angels can be at the same time in the same place?") c. that two angels can't be in the same place, but not for the same reason two bodies can't be in the same place:
There are not two angels in the same place. The reason of this is because it is impossible for two complete causes to be the causes immediately of one and the same thing. This is evident in every class of causes: for there is one proximate form of one thing, and there is one proximate mover, although there may be several remote movers. Nor can it be objected that several individuals may row a boat, since no one of them is a perfect mover, because no one man's strength is sufficient for moving the boat; while all together are as one mover, in so far as their united strengths all combine in producing the one movement. Hence, since the angel is said to be in one place by the fact that his power touches the place immediately by way of a perfect container, as was said (Article 1), there can be but one angel in one place.
He writes in Article 1:
It is befitting an angel to be in a place; yet an angel and a body are said to be in a place in quite a different sense. A body is said to be in a place in such a way that it is applied to such place according to the contact of dimensive quantity; but there is no such quantity in the angels, for theirs is a virtual one. Consequently an angel is said to be in a corporeal place by application of the angelic power in any manner whatever to any place.
Accordingly there is no need for saying that an angel can be deemed commensurate with a place, or that he occupies a space in the continuous; for this is proper to a located body which is endowed with dimensive quantity. In similar fashion it is not necessary on this account for the angel to be contained by a place; because an incorporeal substance virtually contains the thing with which it comes into contact, and is not contained by it: for the soul is in the body as containing it, not as contained by it. In the same way an angel is said to be in a place which is corporeal, not as the thing contained, but as somehow containing it.