I personally find Pytheas journey most fascinating, even though, interestingly, the later authors in the ancient world were quite dismissive of many of his claims. As for the location, Ptolemy for instance places Thule north of the Orcades (Orkney Isles). If we follow that line northwards, we end up at the Shetland Islands. However, Ptolemy's Thule is clearly marked as a larger land mass, not as an island so the Shetland Isles do not fit this description well. What speaks against Iceland is the fact that Thule is described as actually having inhabitants (unlike Iceland, which was not settled until the 9th century), and also Strabo recounts details that it's denizens have millet and honey. So, I'm personally in favour of Thule being Norway, rather than anything else.
True, but then again take the reference to the Frozen Sea and the Midnight Sun. And as for the references of Thule being inhabited, from what I have read they could refer to other parts of the "Prettanic" isles. I found an article that sums it up quite well (The Problem of Pytheas' Thule by Ian Whitaker (1981)):
The first classical author whose writings have survived is Strabo. Here is what he wrote of Pytheas' voyage:
... Pytheas, by whom many have been misled; for after asserting that he travelled over the whole of Britain that was accessible Pytheas reported that the coastline of the island was more than forty thousand stadia, and added his story about Thule and about those regions in which there was no longer either land properly so-called, or sea, or air, but a kind of substance concreted from all these elements, resembling a sea-lungs, a thing in which, he says, the earth, the sea, and all the elements are held in suspension; and this is a sort of bond to hold all together, which you can neither walk nor sail upon. Now, as for this thing that resembles the sea-lungs, he says that he saw it himself, but that all the rest he tells from hearsay. That, then, is the narrative of Pytheas, and to it he adds that on his return from those regions he visited the whole coastline of Europe from Gades to the Tanais.
2. Now Polybius says that, in the first place, it is incredible that a private individual-and a poor man too-could have travelled such distances by sea and by land; and that, though Eratosthenes was wholly at a loss whether he should believe these stories, nevertheless he has believed
Pytheas' account of Britain, and of the regions about Gades, and of Iberia; but he says it is far better to believe Euhemerus the Messenian than Pytheas. Euhemerus, at all events, asserts that he sailed only to one country, Panchaea, whereas Pytheas asserts that he explored in person the whole northern region of Europe as far as the ends of the world--an assertion which no man would believe, not even if Hermes made it.
Concerning Thule our historical information is still more uncertain, on account of its outside position; for Thule, of all the countries that are named, is set farthest north. But that the things which Pytheas has told about Thule, as well as the other places in that part of the world, have indeed been fabricated by him, we have clear evidence from the districts that are known to us, for in most cases he has falsified them, as I have already said before, and hence he is obviously more false concerning the districts which have been placed outside the inhabited world. And yet, if judged by the science of the celestial phenomena and by mathematical theory, he might possibly seem to have made adequate use of the facts as regards the people who live close to the frozen zone, when he says that, of the animals and domesticated fruits, there is an utter dearth of some and scarcity of the others, and that the people live on millet and other herbs, and on fruits and roots; and where there are grain and honey, the people get their beverage also, from them. As for the grain, he says,--since they have no pure sunshine--they pound it out in large storehouses, after first gathering in the ears thither; for the threshing floors become useless because of this lack of sunshine and because of the rains.
...the parallel circle that runs through Thule (which Pytheas says is a six days' sail north of Britain, and is near the frozen sea)...
For not only has the man who tells about Thule, Pytheas, been found, upon scrutiny, to be an arch-falsifier, but the men who have been to Britain and lerne [Ireland] do not mention Thule.... However, any man who has told such great falsehoods about the known regions would hardly, I imagine, be able to tell the truth about places that are not known to anybody.
Now Pytheas of Massilia tells us that Thule, the most northerly of the Britannic Islands, is farthest north, and that there the circle of the summer tropic is the same as the Arctic Circle. ... But in my opinion the northern limit of the inhabited world is much farther to the south than where the summer tropic becomes the Arctic Circle. ... But Pytheas, who misleads people everywhere else, is, I think, wholly in error here too.
Strabo later makes one last reference about Pytheas leading men astray.
So here a synthesis of what Strabo (who, as we can see, considered Pytheas' voyage false) asserted:
- Pytheas claimed to have traversed Britain, for the coastline of which he gave the precise measurement of 40,000 stadia.
- In Thule was to be found a strange condition, neither land nor sea nor air, but some sort of substance mixing these elements, resembling the sea-lungs [normally the name of a type of jelly-fish], which it was not possible to cross either on foot or by ship.
- He saw this particular condition himself; the rest of his account is hearsay.
- After returningf rom 'these regions' he traversedt he coastline of Europe from Gades to the Tanais (today known as the river Don).
- Pytheas has provided unspecified false information about other regions that are known to science--a charge never amplified.
- Pytheas does, however, have a competent knowledge of astronomy and mathematics.
- There are some people who live 'close to the frozen zone' who are lacking many types of animal and plant, and who live on millet and herbs, as well as root-crops. They do have grain and honey, and, it would seem, some kind of fermented liquor, but the climate
precludes open threshing areas. There is much rain and no sunshine.
- Thule is six days' sail north of Britain, and is near the frozen sea.
- Thule is the most northerly of the British Isles, and is on the Arctic Circle.
- Strabo does not specifically say whether he has read Pytheas at first or second hand, but he does say that Polybius has branded him a liar, and that Eratosthenes did not know whether to believe his account or not.
Now then, Strabo derives his account from 2 sources, both of which are mostly lost:
- Polybius was a Greek Stoic writer and soldier of the 2nd century BC. He mostly discredited the veracity of Pytheas' voyage on the grounds that he was a poor man and could not have funded such an expedition.
- Eratosthenes was a Greek mathematician and poet of the 3rd century BC. He apparently believed the veracity of Pytheas' voyage, although he was not sure on how reliable his account was.
The other main source for Pytheas' voyage is Pliny the Elder, writing about Britain:
...the light nights in summer substantiate what theory compels us to believe, that, as on summer days the sun approached nearer to the top of
the world, owing to a natural circuit of light the underlying parts of the earth have continuous days for 6 months at a time, and continuous nights when the sun has withdrawn in the opposite direction towards winter. Pytheas of Marseilles writes that this occurs in the island of Thule, 6 days' voyage north from Britain...
Pytheas of Marseilles states that north of Britain the tides rise 80 cubits [37 metres].
The most remote of all is Thule, in which, as we have pointed out there are no nights at midsummer when the sun is passing through the sign of the Crab, and on the other hand no days at midwinter; indeed some writers think this is the case for periods of six months at a time without a break.... One day's sail from Thule is the frozen ocean called by some the Cronian Sea.
So, here is a synthesis of what he writes:
- In some northern country there are six months of continuous day followed by 6 months of winter darkness. (This statement is not explicitly attributed to Pytheas, and is contradicted later.)
- Pytheas says that the island of Thule is situated six days' voyage north of Britain.
- Somewhere north of Britain there are tides of 120 feet.
- In Thule there is no night at midsummer, and no day in midwinter. Some writers think that these periods each last six months.
- One day's sail north of Thule is the frozen sea--presumably pack-ice.
Pliny seems to have derived his statements mainly from the Greek geographer Hipparchus, who lived during the 2nd century BC.
There is also another writer whose writings did not survive but who is known to have written favourably about Pytheas' work, the Peripatetic philosopher Dicaearcus of Micena (who died around 285 BC).
There are also later sources of Pytheas' voyage, for example the Stoic philosopher of the early 1st century BC Posidonius, whose works have not survived. Someone whose works have survived, however, is the 1st century BC astronomer Geminus of Rhodes, who writes:
Pytheas says that the barbarians revealed to us the sleeping place of the sun; it was found that in these regions the night was very short, lasting in some places two hours, in others three.
Two things can be derived from this:
- In the place to which these observations allude (Thule?) there was a barbarian population, members of whom Pytheas met.
- In this same place the night lasted two or three hours. (The season of the observation is not mentioned.)
Pomponius Mela, of the 1st century AD, also briefly mentions Pytheas, and Pseudo-Plutarch, another writer of that century, states:
Pytheas the Massaliote maintained that flood-tides occur when the moon
waxes, ebb-tides when the moon wanes
This tells us that Pytheas is the first recorded writer to note the the relationship between the moon and the tides. We can thus say about Thule:
- There is a connexion between the waxing of the moon and the occurrence of flood-tides, on the one hand, and the waning of the moon and the incidence of ebb-tides on the other.
Also of the 1st century AD is the Latin geographer Pseudo-Aristotle, who uses Pytheas as a source but does not mention Thule.
Of the 2nd century, there is the Greek writer Cleomedes, who gives little new information, but confirms this:
The 4th century Latin poet Avienus also mentions Thule, but says nothing new. However, the 5th century writer Martianus Capella mentions Pytheas and Thule, and adds the winter night lasts half the year. Therefore, his contribution can be summed up like this:
- In Thule the nights last for six months, which is the winter season.
Finally, there is the 6th century writer Cosmas Indicopleustes, who writes this rather ambiguous passage:
Pytheas of Marseilles, again, in his work concerning the ocean, informs us that when he had reached the remotest parts of the north the barbarous people found there showed him the cradle of the sun, for, in the parts where they live, the nights always have their source.
Now then, we can say that Pytheas wrote his book around 325 BC. Thus, the first known writer to have written about Pytheas would be Dicaearchus (c. 300 BC), followed by Eratosthenes (c. 225 BC), Polybius and Hipparchus (both c. 145 BC). Of the surviving sources, there is Geminus (c. 50 BC), Strabo (c. 8 BC), Pliny, Pseudo-Plutarch (both c. 77 AD), Cleomedes (c. 150 AD) and Capella (c. 439 AD). Capella must be discredited, as the night obviously does not last 6 months. Pliny also provides some contradictory information about the length of the night in winter, and probably greatly exaggerates about the height of the waves. Of the other 11 statements recollected, only 11 mention Thule.
We can thus say the following about Thule:
Thule manifests the strange condition Pytheas saw and compared with the sea-lungs, referred to only by Strabo; Pytheas seems to have visited Thule himself, but he also says that all his other observations are hearsay; there was a population 'near to the frozen zone', who may also have inhabited Thule; Thule lay six days' sail north of Britain, perhaps on the Arctic Circle, although it is also described as the most northerly of the British Isles and one day's sail from the frozen sea; the night at Thule in midsummer either lasts two to three hours or is nonexistent.
The main contradictions seen here is whether Thule is inhabited and how long the midsummer night lasts. Strabo specifically says that Pytheas saw the "sea-lungs" but only heard the rest. He also does not specifically say that the population he describes is on Thule, but rather "close to the frozen zone". The two statements by Geminus of Rhodes seem not to refer to Thule, as he mentions a barbarian population and that the night lasts around 3 hours.
Now then, the proposed candidates for the location of Thule have been the Shetlands, Iceland, the Faroe Islands, and Finland.
Firstly, there is the misapprehension that Iceland must be excluded as it had no population at that time, however, Strabo does not refer specifically that the northern people he mentions lived in Thule. One should also note the finds of Roman coins in Iceland dating to the 3rd century AD, which may point out others had arrived there in Antiquity.
The Shetland Islands can be ruled out due to the fact that the night is longer than 2-3 hours at midsummer and it is not on day's sail from pack-ice. Another objection to the Shetlands (and perhaps Norway) being Thule is that Thule is not described as a group of islands.
