The final step in my article is to analyze the ethical aspects. Husserl states that we should ultimately justify our actions “from autonomous insight”, but also cautions that: “then I would not be allowed to use any logarithmic table, any calculating machine, without having knowledge in all seriousness of the theory.” (Hua XLII, 272). Husserl hence acknowledges that this is impossible in practice for us as individuals. The world is far too complex and so we cannot avoid using tools to understand and act in the world:

Science, according to its own conception, is as infinite as the world and can only be realised in the finitude of a scientific community in stages and by using symbolic aids [Hilfsmittel der Symbolik], by sharing the lived insights [lebendigen Einsicht] among a communicative scientific community. (Hua XLII, 273, n. 1)

Symbolic aids do not only enhance our capacity for (scientific) knowledge, but also our capacity for (ethical) action. If we have the obligation to choose the greater good, then we have an obligation to use our symbolic aids. Even if we do not have the required “autonomous insight” as individuals, we have it collectively, as a community. In the scientific community, “autonomous insight” cannot mean that everyone needs to know everything. Division of labor is unavoidable and is based on trust in the respective specialization (Hua XLII, 274, n. 1. Also see Hua XVIII, § 71). This division of labor is enabled again by the use of symbolic aids for obtaining, storing, and communicating knowledge. However, Husserl warns us in the Crisis about this progressive technicization of science:

Thinking becomes a thinking with surrogates, that has its own evidence in the context of this technique, its own goals, its own tasks and solutions, which diverge from the evidence of goals, tasks, solutions, that were originally indicated by such words and symbols. (Hua XXIX, 35)

Husserl’s terminology from the 1890s for symbolic intentionality in the context of mathematics is now used in the same way for science at large. When we convert concepts into signs, manipulate the signs according to an algorithm, and then convert signs into concepts, we risk forgetting our original aims and values for which the whole symbolic technology was invented in the first place (see i.a. Hua XLII, 430, 436). There is a risk of loss of meaning in the “thoughtless” intermediate phase without awakened reason as a historical-critical reflection (see e.g. Hua XXIX, 190).

If science and rationality are to guide humanity and help it flourish with the tools it develops, the trust and division of labor in science and society need to be well-founded on historical-critical thinking that can provide the ultimate proper, insightful justification. This requires a thorough analysis of symbolic intentionality and symbolic technologies: how humans and machines use signs. Husserl’s theory of symbolic computation can still help us today: in order to understand the world and act ethically in it, we need to understand the tools to which we have outsourced our thinking and the theories on which this very possibility is based.