I was wondering about the word thalatta, which we can find in its most icastic form in Xenophon’s Anabasis, on the lips of the Greek mercenaries (Θάλαττα! Θάλαττα!). We don’t know the exact origin of the word, it’s a kind of an unicum in philology; anyway, what we know is that in Greek mythology Thalassa is a primeval spirit of the sea from Pre-Greek past.
This means that the word has a “divine root” and probably shares something with Hebrew Tehom (תְּהוֹם), the Abyss, the Great Deep of primordial waters, which itself is a cognate of Akkadian Tamtu and was equated with Sumerian goddess of the ocean Tiamat.
I was trying to remember if there are others European language that indicates the sea with a word starting by the letter “T” (in Modern Greek “sea” is still Θάλασσα), and I can actually say that there are two terms which share the same origin: Turkish deniz and Hungarian tenger, both coming from Proto-Turkic *teŋri/*taŋrɨ, “God”, “Sky”, “Heaven” (Modern Turkish has also Tanrı, still a synonym of “Allah” in some idiomatic expressions as “Tanrı bilir”). Here’s a “God” from another abyss, the blue expanse, the sky.
I don’t know if this hypothesis has any plausibility from a philological perspective, but there are some psychological and cultural indications for that. For example, French philosopher Gaston Bachelard in a study on Edgar Allan Poe examines the writer’s conception of water as mare tenebrum, the “symbolic substance of death” (L’eau et les rêves, “Water and Dreams”, 1942).
Furthermore a disciple of Bachelard, the French anthropologist Gilbert Durand, wrote that “in the work of Poe […] ‘superlative water’, the true poetic aquaster, refers to his obsession with his dying mother. […] [Poe’s imagination] is profoundly morbid, shocked by the death of his mother; however, through the lugubrious, morose, aquatic pleasure can be glimpsed the comforting theme of maternal water.”
Durand also states that “the supreme primordial swallower is the sea […]. The feminised, maternal abyss is, for numerous cultures, the archetype of descent and of the return to the original sources of happiness” (Les structures anthropologiques de l’imaginaire, “The anthropological structures of the imaginary”, 1960).
In addition, he strengthens his speculations with some philological notes taken from Jean Przyluski’s La grande déesse: introduction à l’étude comparative des religions (1950): “The river Don is said to have been named after the goddess Tanaïs. Don and Danubius are, according to Przyluski, Scythian and Celtic deformations of an ancient name for the goddess-mother, analogous with Tanaïs. […] Przyluski reduces the Semitic names of the Great Goddess, the Syrian Astarte, Arab Atar, Babylonian Ishtar, Carthaginian Tanit to a form ‘Tanaïs’, closely linked to ‘Nanai’ which he believes to be an ancient name for water and river.”
Tanaïs (Τάναϊς) appears in ancient Greek sources as both the name of the river and of a city, also called the Maeotian Swamp.
Still following Durand (and Bachelard) we can find a connection between the “diurnal” and “nocturnal” order of imagination, which could mean that God, Sea, Sky, Abyss, Heaven, it all begins with a “T”…
We can also identify more psychological confirmations (always from a “tempered” Jungian perspective) in the essay of Alfred Kallir on “Letter T”, which is included in his most important work Sign and Design: The psychogenetic source of the alphabet (1961).
But this is just a reverie, so please don’t take it seriously (or take it seriously only in the shoes of a Jungian therapist).