The Persistence of Living Beings and Artefacts

Our project on persistence follows up the project "The concept of person and the naturalistic challenge". The first project`s aim was to clarify the ontological presuppositions of the naturalistic accounts of the human person. We pleaded for a wider Aristotelian ontology and concentrated on the relevant concepts of materia, habitus and anima. We worked on related problems of causation, agency and the ontology of time (see appendix). The results achieved led straight into the problem of the diachronic identity of human persons. In the new project we, thus, intend to unveil the ontological presuppositions of the divergent accounts of persistence. (a) We will continue to consider the current debate between perdurantism and endurantism in ontology and the parallel one between eternalism and actualism in the philosophy of time. (b) We will discuss the thesis that it is the individual sortal (the sortal token) to guarantee persistence or diachronic identity. (c) We will concentrate on the thesis that the specification of the sortal or natural kind depends on the physical constitution and the kind of activity of the individuals falling under it. The identity of a specific individual and its activities are intertwined. The key notions to be examined in our research are therefore `disposition`,`capacity` and `function`. We are convinced that a thorough analysis of the diverging views of persistence and an appreciation of strengths and weaknesses of the related positions helps clarifying the presuppositions of the ongoing debate on the ontological status of the human person, living beings in general and artefacts. A thorough analysis and explication of the concept of persistence through time shall finally conduce to successful interdisciplinary research (e.g. ontology, developmental biology, embryology, applied ethics).

What guarantees personal identity over time? When do human persons begin to live and when do their lives come to an end? Is research into personal identity a purely theoretical endeavour or should it consider the perspective of practical agents as well? In this research project we tackled these and other related issues. In particular we investigated the relationship(s) between the metaphysics of personal identity and related practical issues such as self-concern, personal survival, moral responsibility, compensation or end of life decisions. Crucial for the current debate is the distinction between the persistence of the human organism and personal identity. The former notion refers to the existence in time of human organisms, the latter to the existence in time of human persons. Given that human organisms and human persons are not co-extensive, since the former might continue to exist even while the latter do not (for instance, if all higher cognitive capacities are destroyed), we can distinguish between biological and psychological theories of personal identity. Biological theories (or animalism) assume that the biological functioning of the human organism, that is, the persistence of unified and appropriately interacting metabolic processes, is the essential feature of human persistence. Accordingly, proponents of this approach consider human personhood to be not a metaphysical but a practical notion. Psychological theories are motivated by thought experiments which suggest that generally human persons favour the continuity of their mental life over mere continuity of their organism. Since psychological theories begin with the causal connections between earlier and later psychological states, the concept of the human person ought to be reconstructed from these causal relations for practical purposes. Both approaches face well-known problems such as graduality and fission. One way to side-step them is to endorse a third account of personal identity, the so-called simple view. According to this approach, personal identity is fundamentally basic. Personal identity is only conceivable from the inside, that is, from ones first-person perspective. The problem with this account is that, although it lends itself to an analysis of synchronic personal identity, it has trouble accounting for diachronic personal identity. Practical considerations remind us that a diachronic account is indispensable, for most practical decisions are future-oriented. Our research led us to conclude that all three accounts can reconstruct the relationship between the metaphysics of our identity and practical concerns, but that they do so in different ways. But each account faces intrinsic theoretical problems, and when we add considerations from practical rationality no theory is clearly preferable over its rivals. This might be due to the double nature of human persons: On the one hand there are good arguments that our nature is biological, and on the other hand our complex psychological life and our first-person perspective strongly suggest that our nature goes beyond biological features. We thus conclude that the practical concerns motivating the investigation into personal identity turn out not to be univocal, as is typically assumed, but rather that different practical concerns may actually be motivate different concepts of personal identity. However, it seems clear that naturalistic-reductionist approaches (such as the biological or psychological accounts) do not suffice to tackle the whole array of questions concerning personal identity be it from a theoretical or a practical perspective.