This article, originally published in Finnish, provides a systematic introduction to the nature, subject matter, methods, and epistemic aims of metaphysics. It characterizes metaphysics as a discipline concerned with understanding the fundamental structure of reality as a whole, including questions about what exists, what kinds of entities there are, how they exist, and how they depend on one another. The discussion surveys central metaphysical topics such as ontological categories, essence, modality, causation, laws of nature, and fundamentality, and presents major contemporary (...) approaches, including neo-Quinean ontology, grounding-based metaphysics, and formal ontology. Finally, the paper defends the view that metaphysical inquiry is unavoidable, as any attempt to understand reality presupposes metaphysical commitments, even in its critiques. (shrink)

Conventional elements play an integral role in measuring time. Clocks unavoidably require a chosen standard of synchrony. The periodic process selected for the standard is not imposed upon us in any way. Conventionalism, in this regard, offers an insightful perspective on temporal measurement. The strong formulation of this doctrine is, however, questionable. After elaborating on strong conventionalism, it will be argued that it has three downsides: (i) it fails to properly distinguish between highly stable natural processes and complete randomness, as (...) periodicities differ in terms of regularity; (ii) it does not explain that a clock actually measures something, to wit, parts of its own path along its worldline in spacetime; (iii) and relatedly, it omits the distinction between a temporal interval as a physical quantity and the arbitrarily chosen unit of time, leaving the distinction between temporal quantities and units a mystery. (shrink)

As I understand, Jani adopts (at least) two general views about the nature of time: block universe eternalism and three-dimensionalism. There are different varieties of these views, of course, but the two main views are usually not linked together. In what follows, I’m going to ponder whether the two can coherently coexist.

To provide metaphysical grounds for the physics of her time, Du Châtelet argued for the notion of an active force. This was different from the impressed force in Newton’s second law. The former force was a property of a body, whereas the latter was an external cause. I shall study this discrepancy and argue that the interactive concept of force in Newton’s third law is consistent with Du Châtelet’s standards for an intelligible physics. Consequently, the interaction entailed by the law (...) of universal gravitation complies with Du Châtelet’s principles of human knowledge. (shrink)

We may distinguish two interpretations of the relation between Newton’s natural philosophy and Hume’s science of human nature. The first interpretation can be called ‘traditional,’ the second ‘critical.’ This article will not side with either readings of Hume’s Newtonianism (or with some middle positions). Instead, essential points of confluence and divergence will be discussed.

Our dear friend and mentor Jani Hakkarainen reaches his half-century on December 23rd, 2025. Jani has been a constant presence for almost all of our academic lives. This includes, but is not limited to, his teaching, organizing the talk series at the Tampere University philosophy unit, arranging conferences on contemporary and historical philosophy, walking the corridors in his Tappara-slippers, stopping for an insightful chat at the coffee table, and often giving detailed, but always fair, criticism on our philosophical ideas and (...) writings. -/- In order to celebrate Janis’s birthday, we have invited a group of his colleagues and students to write articles on topics he has himself contributed to, or at least would find interesting and stimulating. This anthology is our birthday gift for him. -/- The anthology is divided into five sections based on a larger theme of the papers, with these themes being related to one of the several fields of study Jani has partaken in during his philosophical career. It should be noted that, due to Jani’s love of 70’s progressive music, each section is titled after a song or a piece of lyric from a progressive rock band’s catalogue (including Genesis, Emerson Lake & Palmer, Rush, Pink Floyd, and King Crimson). (shrink)