A Parting of the Ways: Carnap, Cassirer, and Heidegger by Michael Friedman is a book about the history of the philosophy that already gives away its topic in its title. In the beginning of the 20th century, philosophers who had previously engaged in constructive dialogue with each other parted ways and setup two ideological camps that would dismiss and ignore each other - analytic philosophy and continental philosophy. The book is about the confrontation of two of the philosophers whose disciples would split off into different camps. Rudolf Carnap, a member of the Vienna Circle, was one of the leading lights in the logical positivism movement of analytic philosophy. Martin Heidegger's Being and Time took philosophy into the direction of phenomenology, existentialism, hermeunetics, the three key movements that now dominate continental philosophy. Freedman shows where their traditions diverged from a common starting point of Immanuel Kant's philosophy of transcendental idealism. A third thinker, the lesser known, Ernst Cassirer, is introduced into the discussion for the purpose of indicating how the continental and analytic traditions can be reconciled, because Friedman believes that his Cassirer's philosophy serves as a valuable compromise that balances out the more extreme tendencies of the other two philosophies, Carnap's being too scientific and not adequately existential and Heidegger's favoring existential considerations over science.

So how did Carnap's work emphasize the scientific and mathematical but deemphasize the existential human factors? Carnap's work was involved in deemphasizing the psychological and empirical basis of sense perception as a way of grounding mathematics, physics, and science seeking instead to establish their basis in a system of formal logical relations; hence scientific and mathetical principles were found to be rooted in a logical structure and not constituted out of the combination of human mental cognition and sensual perception of the empirical world. That's not to say that these processes played no part; its not that he considered that they played no essential part. However anyone arrived at the logical positions of the axioms of science and mathematics did not matter; they were objectively valid and incapable of being anything different despite the variations of the psychological states, mental capacities, and actual empirical observations of any person.

Heidegger, as a proponent of continental philosophy, took a completely different view. He frowned upon scientific theories, that became more and more complicated and removed from actual human experience. Hence, Heidegger emphasized a more empirical and non-theoretical role for philosophy. Philosophy was not to be conceived in terms of an abstract subject with an abstract consciousness, who was able to perceive abstract theories. Instead, it was to be seen from the point of a view of a concrete human being who had goals, and lived temporally, evaluating the past and projecting himself toward the future. Freedman chides both Heidegger and Carnap, and their respective camps of continental and analytic philosophy to be too narrow-minded. Complex theoretical physics, such as the theory of relativity, were not to be taken as the truth of philosophy because philosophy to embrace the more human truths of experience and beings. Freedman appreciates Heidegger's insights into how philosophy needs to consider subjective factors but is not so happy with Heidegger's degradation of scientific and mathematical reason to a 2nd rate status.

Freedman finds the antidote to Heidegger's neglect of scientific and mathematical reason and to Carnap's neglect of subjective factors of concrete human beings in the philosophy of Ernst Cassirer, who finds room for both objective science and subjective experience in his work. Cassirer revives the Kantian notion of two realms of nature and freedom. Natural language describing the world of everyday objects, their spacial and physical relations, is something that he takes to derive as a necessity of our everyday relation with the concrete material world. Science, he takes to be the theoretical development of the tendency to understand the natural world, that albeit becomes so highly complicated and theoretical that it indeed seems highly removed from "common sense" perception, reversing intuitive beliefs of a stationary earth and the moving sun, the existence of space and time, energy and matter as independent, unrelated elements.

Unlike Heidegger, Cassirer doesn't believe that the removal of science from the truths we intuitively perceive from everyday experience means that we have to privilege the latter over the former.. Cassirer gives everyday experience its own separate function. Here Cassirer draws on Kant, who in the Critique of Judgment asserted that we use our faculties of judgment not only for determing the natural status of the world, but also in creating a semi-fictional, aesthetic, non-scientific judgements in order to regulate our psychological, moral, and aesthetic needs. In his Philosophy of Symbolic Forms, Cassirer agrees with Kant that the very same rational abilities that perceive a scientific, natural structure of the world, also form a set of concepts for a mythical interpretation of life. The only difference is that the subjective imaginations produce a wide variation in sets of mythological concepts that are used to interpret reality. This very belief of Cassirer's takes Heidegger's philosophy into consideration. Heidegger said that concrete human realities - moods, temporal considerations such as expectation, anticipation, and recollection, as well as culturally received norms of society - inform and color human reason. All these factors are taken into account by Cassirer as he understands that the mythical understanding of reality is created out of subjective needs.

The strength of Cassirer's work lies in that it equally embraces both the human experience of the continental tradition and philosophy's goal of accounting for foundations of modern science and mathematics like analytic philosophy. Freedman admires him for realizing a vision of philosophy true both to science and spirituality, whereas Carnap and analytic philosophers emphasize the first at the expense of the latter, and Heidegger vice-versa. Freedman's clear insistence on championing Cassirer's work is not coincidental. Unlike Carnap and Heidegger, Cassirer's work is hardly studied of referred to in the academic circles of philosophy.