What's actually happening
Neptune takes about 165 years to complete one circuit of the zodiac, spending roughly 14 years in each sign. Capricorn is a cardinal earth sign ruled by Saturn. The Neptune in Capricorn transit that ran from roughly 1984 to 1998 is the astrological background of the late Cold War, the collapse of the Soviet Union, and the generation born into the idealization of economic structures and professional ambition.
What the tradition makes of it
Neptune in Capricorn places the spiritual longing inside the institutional and the structured. The organization, the career, the achievement — these become vehicles for something that feels like transcendence. The successful structure is experienced as sacred; the efficient system carries a kind of moral weight.
The tradition notes this as a period during which idealism about institutional forms tends to be high — and the eventual disillusionment equally dramatic when the institutions reveal their limits.
The shadow is the spiritual bypass that uses achievement as a substitute for inner development — the accumulation of credential and status as a way of not attending to what is actually unresolved.
How to actually use it
Build the structure in full awareness that the structure is not the end. The discipline of Saturn and the idealism of Neptune can coexist when the structure is genuinely in service of something larger — when what is being built is understood as a form for meaning rather than as meaning itself.
When in doubt
What is this structure actually in service of — and is that still true?