It produces meditation products, including guided meditations and "Sleep Stories". It is a significant theological work, featuring spiritual meditations and insights. In April 2007, he released "Hudson River Wind Meditations", an album of ambient meditational music. The result is like a diary, or handbook of philosophical meditations. This subgenre is based on meditations (or thoughts). He described this inner faculty when writing in Latin in his "Meditations on first philosophy". He issues this idea in his Meditations on First Philosophy. The book also featured a number of discussions and meditations on age. In his "Meditations", Marcus Aurelius defines several such practices. Elisabeth of Bohemia also corresponded with Descartes on the "Meditations". A young Augustine experimented with, but failed to achieve ecstasy using the meditations of Plotinus. To the "Meditations" was added a Latin translation by Xylander who also included brief notes. He was a stoic philosopher and wrote the "Meditations". The historical impact of the six meditations has been divided. This effect is especially evident in Coltrane's albums "Meditations" and "Stellar Regions".