The planet Neptune was discovered by German astronomer Johann Galle, near Deneb Algedi (δ Capricorni) on 23 September 1846, as Capricornus can be seen best from Europe at 4:00am in September (although, by modern constellation boundaries established in the early 20th century CE, Neptune lay within the confines of Aquarius at the time of its discovery).
They rightly assumed that he could not effectively evaluate and cope with the world until he fully understood his personal psychological balance.
Self Knowledge. It was axiomatic to the mystic philosophers of old that the first step in personal maturity could be expressed in the aphorism: “Know thyself.”