The River Lethe was one of the rivers of Hades in Greek mythology. Exposure to its waters was held to lead to loss of memory, or, more intriguingly, a state of "unmindfulness" and oblivion. From this origin, it has re-appeared throughout western culture, from Dante to Tony Banks's first solo album (River Lethe in popular culture, Wikipedia).

By providing the alternative spelling of Leith, Alasdair Roberts 'doubles' this meaning with the Water of Leith, a river that runs through Edinburgh, and co-locates ancient Greek and contemporary Scots mythology.

The idea of eternal return is bound up with memory, with cultures being compelled to repeat and confront the missteps of the past. So the oblivion of forgetfulness provided by the endless Lethe provides a form of antidote or escape.

In interview with Tyler Wilcox in 2009, Alasdair Roberts referred to the

specifically Jungian references to the "sermons seven" and mandalas... it's like a quest song against conflict and towards individuation. I know a lot of people with strong political or religious convictions whose musical and artistic practice is guided by that – in some ways I envy that kind of certitude, but I suppose my thing is always about flexibility, multiplicity, confusion wanting to reflect the turmoil of reality... always trying to remember that the oar in the ocean is a winnowing fan on dry land.'