Abstract objects like properties and propositions, I believe, can be construed as the result from reification, the metaphysical counterpart of nominalization. My talk explicates reification as higher-order construction, combining two recent alternatives to classical platonism: constructionism and higher-order metaphysics.

Die Debatte über personale Identität konzentriert sich traditionell auf die Frage, unter welchen Bedingungen eine Person zu verschiedenen Zeitpunkten als dieselbe Person gelten kann. Der psychologische Ansatz basiert auf der Annahme, dass psychologische Kontinuität die zentrale Bedingung personaler Identität ist. Diese Annahme wird jedoch durch den Zirkularitätseinwand infrage gestellt. Der biologische Ansatz verweist zur Klärung der personalen Identität auf die Identität des menschlichen Organismus und geht davon aus, dass beide zusammenfallen. Allerdings bleibt oft unklar, worin genau die Bedingungen menschlicher Identität bestehen, sodass eine bloße Verschiebung des Problems droht. Die Philosophie der Biologie bietet hier eine bisher unterschätzte Perspektive: Die Debatte um biologische Individualität enthält aufschlussreiche Überlegungen zu den Bedingungen der Identität von Organismen. Insbesondere der Closure-of-Constraints-Ansatz kann genutzt werden, um eine biologisch fundierte Antwort auf die Frage nach den Bedingungen menschlicher Identität zu liefern und damit die Debatte über personale Identität zu bereichern.

In this paper, I analyze the relationship between us and our digital avatars. Adopting a four-dimensionalist metaphysics, I argue that persons are “hybrid” fusions whose temporal parts are partly located in virtual and non-virtual worlds. Virtual parts are defined as temporal parts existing in virtual worlds, making the relationship between our biological persons and our digital avatars akin to the one between our present self and our past self. I contend that if we characterize persons as maximal aggregates of non-virtual and virtual parts, we can better understand why responsibility for actions in virtual worlds ultimately resides with the people we see and interact with in the biological world. Digital avatars, while not persons themselves, function as non-maximal temporal parts of a person, and then their actions do not merely reflect on persons but are their actions.

I take into consideration a possible objection based on a version of Johnston's (2016) "personite problem", namely the “avatar-personite problem”: biological persons and their avatars may have opposing interests, complicating responsibility attribution and accountability. I maintain that Priority Perdurantism (Skrzypek, 2024) offers a robust solution to the avatar-personite problem and responds to Sweeney's (2023) concerns about the "epistemic gap" and responsibility attribution.

We present a dilemma: either we consider the aptness criterion of Independence to be unnecessary, or we accept the distinction

between default and deviant behavior as outlined in the causal modeling literature. The current work addresses positions that advocate

for non-psychological solutions to resolve structural isomorphism,

explicitly focusing on McDonald’s solution, which introduces a new aptness requirement known as Evident Mediation, framed in purely structural terms.

We show that in cases where this new requirement introduces an additional variable that leads to a positive reversal of the causal verdict,

breaking therefore, the isomorphism between models under examination, there is a possible intervention on the added variable leading to a metaphysically

impossible scenario. Hence, the modified model violates the criterion of Independence. Ultimately, in the context of the inquiry, this does not satisfy Woodward’s criterion of Independent Fixability, which is necessary for models to count strictly as causal. In conclusion, although both sides of the dilemma present advantages and disadvantages, we underline that the structural solution of adopting McDonald’s aptness criterion outweighs its benefits. Until a more effective constraint that enhances Evident Mediation emerges to address these shortcomings, introducing the default/deviant distinction remains the more favorable approach to avoid structural isomorphism.