This article deals with the relationship between philosophy and science in the writings of Karl Jaspers and with its reception in the wider scholarly literature. The problem discussed is how to characterize the relationship that exists between science—defined on pure Kantian grounds as a universally valid knowledge of phenomenal objects—and philosophy—conceived by Jaspers as the transcending mode of thinking of personal Existenz rising towards the totality and unity of Being. Two solutions to that problem arise from Jaspers’s writings. The oppositionist view is based in his earlier philosophy of Existenz. It describes the discrepancy between determinateness, bestowed by science to its objects, and freedom of self-determination, which is both a synonym and a condition of possibility for Existenz. The reciprocal view is based in Jaspers’s later works, where he focuses on exploration of his concept of Being (das Umgreifende). By contrast with most of Jaspers’s commentators, the present interpretation is anchored in a developmentaland contextual understanding of Jaspers’s thought. Showing the transcendental background of this topic, the proposed interpretation allows us to abstain from viewing the two solutions as incoherent or contradictory and instead to see them as constitutive of a single philosophical course.

In this essay, we notice that the priority of persons, the unbridgeable political gap between persons and mere things, corresponds to a special sort of moral and legal treatment for persons, namely, as irreplaceable individuals. Normative language that conflates the category of person with fungible kinds of being can thus appear to justify destroying and replacing human beings, just as we do with things. Lethal consequences may result, for example, from a common but improper extension of the word “value” to persons. Theattitude and act called “respect” brings forth much more adequately than “value” the distinctively individual priority of persons, allowing our common humanity to be a reason for each person’s separate significance. Unless we focus on the respect-worthiness of humanlife rather than on its value, we will not be able to argue coherently against those who think its destruction permissible.

The paper finds at least nine material differences between acts in history and entities in nature. (1) Nature rules out intentional structures essential to human acts. (2) Material trajectories in nature are unique, but acts in history are open to multiple interpretations.(3) In terms of set theory, history is bigger than nature. (4) Historical acts cannot be demarcated from the rest of the world by interactions with the world at a boundary. What happens far off-stage can transform human acts in focal view. (5) Human acts can be revised after the fact. Material trajectories in nature cannot be. (6) Meaning and interpretation are constitutive of human acts. (7) Human acts may involve physical motions; they do not always do so. (8) Human acts always involve final causes. (9) Efficient causes in nature determinetheir effects; efficient causes in history may not.

Richard Brandt’s “Second Puzzle” for utilitarianism asks: What is meant to count as benefit or utility? In addressing this puzzle, Brandt dismisses “objective” theories of utility as prejudging substantive moral issues and opts for “subjective” theories of utility based either on desire-satisfaction or happiness, so as to welcome people with a variety of substantive moral commitments into his utilitarian system. However, subjective theories have difficulties finding principled grounds for elevating one desire over another. Brandt attempts to circumvent the difficulties through his “reformed definition” of rationality, a definition that hinges on his notion of cognitive psychotherapy. Cognitive psychotherapy asserts that a desire is rational only once it is vividly exposed to relevant, available information. I argue that Brandt’s notion of cognitive psychotherapy tacitly builds substantive metaphysical and ethical commitments into his reformed definition of rationality, thus rendering his theory of utility an objective theory. Answering Brandt’s “Second Puzzle” forces not only Brandt, but also utilitarians more generally, to take up substantive metaphysical and ethical commitments from the outset, commitments that substantially predetermine the outcomes generated by their utilitarian systems.

Based on an earlier analysis that tries to show that existence is a real predicate, I now argue that Descartes’s dream and malicious demon arguments are fallacious. An object that stands external to me (i.e., that exists) is the one thing that I cannot produce by my dreams, and, on phenomenological grounds, I am immediately experiencing an existing object right now. Therefore, in accepting that it is a logical possibility that I am dreaming, either I illicitly conflate an existing object and an object of a dream, or Descartes’s claimthat there are never any sure signs by which being awake can be distinguished from being asleep is a presupposed but unfounded premise. Similarly, Descartes’s malicious demon argument must also be rejected.

I argue that the Aristotelian definition of motion,“the act of what exists potentially insofar as it exists potentially,” and the mover causality principle,“whatever is moved is moved by another,” are compatible with Newton’s First Law of Motion, which treats inertialmotion as a state equivalent to rest and which requires no sustaining mover for such motion. Both traditions treat motion as such as requiring an initial, generating mover but not necessarily a sustaining motor. Through examining examples of motion as treated by Newtonian physics, and through arguing that potential energy is Aristotelian potentiality, I argue that the First Law is understandable according to the Aristotelian definition as an incomplete act with a twofold ordination of the same potentiality. I then propose that, through the notion of spacetime, Special and General Relativity instantiate motion as a unity of differentiated prior and posterior parts that do not coexist in reality.