The issue of instrumentality is big in architecture theory circles, where it stands in general for the non-poetic, reductionistic, and purely ends-to-means relation to the world. Phenomenology has a big stake in opposing instrumentality, particularly as it is evidenced in technology, militarism, colonialism, and the expansion of capitalism as it overwhelms local cultures and erases all sense of place. Is instrumental cause, a "subordinate" form of causality added to Aristotle's classic four forms (efficient, final, material, formal) at the base of instrumentality? The case is not clear. Looking at the history of instrumental cause, it is as often employed to explain the effectiveness of religious practices as to characterize pure means to ends.
Instrumental cause, because it is habitually placed opposite values that are utopian, difficult to articulate, idealistic, points to the dependence on the logic of the binary signifier. The binary signifier is, in turn, an impasse for discourse. Pretending to look for some balance point, some mediation or happy middle, none can be found because each terms generates its opposite. In the process, the “valued term” (poetic thinking in our case) is sublated, or “occulted” — placed beyond the bounds of discourse, held to be “ineffable.” As a result, the occulted signifier operates “metonymically,” as an absence that must echo at a distance. The real developments of understanding are, thus, “staged” in bad faith. The straw man fallacy is used to fake opposition in need of resolution where there is really the dynamics of dialectic — dialectics that does have poetic and precise forms of signification.
The problem is the Symbolic itself, the networks of symbolic relationships that take up the model of language and attempt to determine meaning in the form of relationships between signifiers and signifieds. Signifiers are circular; one is needed to define the other; there is no conclusiveness, no “hitting the nail on the head.” The experience of meaning is essentially an experience, a "subjective objectivity" so to speak. We cannot back-project this experience onto signifiers and their relationships with elusive signifieds. It has been, in fact, the inherent radical failure built in to signifying chains that has made this experience of meaning possible. In such events, the role of instrumental cause is critical, necessary, and instructive. In other words, instrumentality is not the enemy of “the poetic,” it is the heart and soul. In the history of the use of instrumental cause and its poetic, ethnological, and even shamanistic antecedents, I believe this relationship can not just be proven but shown to be revolutionary.