[2] The book's objective is to challenge the materialistic and dysteleological assumptions of the modern world view, and to set forth evidence for a correspondence between planetary alignments and patterns of human history.

The book attempts to provide an archetypal cosmology to accompany Tarnas's proposed participatory epistemology, "in which human beings are regarded as an essential vehicle for the creative selfunfolding of reality".

These historical-astrological coincidences or synchronicities led Tarnas to further explore the relationship of pivotal moments in Western cultural history to the conjunctions, oppositions, and squares of the outer planets.

In the book Tarnas discusses the correspondences between planetary transits and the biographies of such figures as Friedrich Nietzsche, William Blake, Walt Whitman, and Arthur Schopenhauer.

"[7] Anthroposophist Frederick Dennehy opined in Lilipoh magazine that "Tarnas’ deeply radical hypothesis is that the disenchantment of the modern universe is unreal – the result of a “simplistic epistemology” and moral positioning totally inadequate to the depths, complexity and grandeur of the cosmos.

"[13] In Tikkun magazine Jordi Pigem opined, In the last ten years, landmark works...have been reflecting and kindling a growing awareness that nature is not merely a sum of molecules obeying physical and chemical laws, but a living, sensuous, and ensouled matrix in which we fully participate and belong.

[14]Daniel Pinchbeck, writing in Reality Sandwich, opined that Cosmos was "scrupulously researched and carefully argued", and that it advances "a radical thesis...which seeks to revive astrology as a serious intellectual discipline and provide a cosmological missing link between the human world and the greater universe in which we are embedded."