Years ago, when I was researching Juan Luis Segundo, I went to Montevideo, Uruguay and spent several weeks in the Jesuit archives at Manresa Retreat Center. When Segundo died in 1996, one of his friends gathered his papers and draft manuscripts, put them in boxes, and drove them to Manresa. Among those papers, I found an unpublished manuscript labeled “La fenomenología de Heidegger y la teología.”
Generally, the manuscript engages with Heidegger’s Being and Time. Segundo argues that phenomenology does not exclude theology. One of the points that is fascinating to me is his engagement with the distinguishable terms “existential” and “existentiell.”
In the essay, Segundo focuses on Heidegger’s phenomenology as a method. This complements his own predilection for method over doctrine, and he applies phenomenology as a method in a different way than Heidegger did in Being and Time. In phenomenology, Segundo finds a vibrant approach for understanding logos (word) and aletheia (truth). A focus on exegesis of speech requires Segundo to deal with the typically Heideggerian distinction between the German words existenzial and existenziell.
Segundo’s Spanish translation is existenciario and existencial, which in Macquarrie’s English translation of Being and Time is existential and existentiell, respectively. Segundo’s use of existentiell (Spanish existencial or German existenziell)is consistent with his earlier works. It is the affective and beautiful, e.g. knowing a being through writing a poem. He equates existentiell with the ontic, what is given ‘in fact’.
The existential (Spanish existenciario or German existenzial)relates to the ontological. In order to truly grasp phenomenology, humanity must engage with the exegesis of being itself, not simply exegesis of speech. The existentiell is commonly understood as the sphere of ontic understanding of beings in the world. For Segundo, this finally means engaging with “the fear that is at the root of all fears.”
Segundo gets to this point only through first describing ontic fear and relates it as what follows from ‘various forms of fear’ but it exceeds these forms as a basic mood of fear. The “fear at the root of all fears” is, he says, “no longer existentiell but existential,” no longer ontic but ontological. That is, particular fears are ontic.
Segundo writes, “Phenomenology is not opposed, as we saw, only to empty or falsified concepts, but also to ‘constructions in the air’ and ‘accidental discoveries’ i.e. to everything does not exceed the level of the ontic, of the existentiell seeking this existential-ontological foundation” This leads him to concede to Heidegger a disruption between theology when it is existentiell (i.e. when it is exercised as an ontic science) and phenomenology (when it is applied ontologically) as existential. Summarizing Heidegger, Segundo notes that “phenomenology leads us from the ontic to the ontological.”
Simply put, Segundo finds phenomenology useful. It’s a tool that helps us move from our understanding of ‘what is given’ (ontic) to ‘how we are’ (ontological). Because preaching and serving a church is my day job, the question rings through my head: will it preach? No. At least, not directly. However, understanding how we see the world and challenging people to see the world through a Christ-lens does preach. The ontic is what we find. The ontological is how we exist in what we find. And, talking about how to live or exist in what we find does preach.
 Segundo, La fenomenología: 5.
 Magda King writes, “A distinction must be sharply drawn between fear of the ontic, biological ‘end of life’ (decease), and dread as the basic mood which discloses that Da-sein as a thrown being exists to his end”. Magda King, A Guide to Heidegger’s Being and Time, ed. John Llewelyn (Albany: State University of New York Press, 2001), 153. King’s argument highlights the complexity of describing Heidegger’s distinction between ontic/ontological and existentiell/existentiale.
 Segundo, La fenomenología: 5.
 Segundo, La fenomenología: 6.