The uncertain moral status of embryo models

The ultimate goal of this project is to provide a normative framework for research with embryo models that bears specific attention to the different types of models and the temporality of development. To achieve this end, we need a better understanding of the properties of these models through a clarification of their ontological and epistemological status. As a consequence, the current project is, first of all, a work inspired by philosophy of science on modeling in biology. By doing this, it will provide a conceptual framework suitable to stem cell based embryo models.

One of the first apparent goals is to go beyond the current frameworks that oppose integrated and non-integrated models. The distinction between integrated (or complete) models and non-integrated (or partial) models is indeed the main landmark bioethics today and the one that shapes current regulation proposals and guidelines, e.g., International Society for Stem Cell Research guidelines (ISSCR 2021). According to this distinction, integrated models include all cell types present in an embryo, which is not the case for non-integrated models. There would therefore be models that are close to embryos and would have to be regulated accordingly and other models that would be partial and would consequently not raise particular questions. Theoretically (although it is difficult to judge for many reasons), one can envision complete models that could give rise to a human person if implanted in a womb under the right conditions. In this sense, these “models” would not differ in potentiality from actual embryos themselves – and then we could no longer speak of models.

However, this distinction (integrated/non-integrated) is not satisfactory insofar as there is also no precise and consensual definition of what an integrated or more or less complete model is: up to what level of integration can we go and how to measure “completeness”? For instance, the presence of extra-embryonic tissues does not make a model complete and implantable. This distinction omnipresent in guidelines is still fraught with uncertainties and needs clarification. More generally, the criteria for comparing models and embryos vary depending on the research objectives and the context in which this comparison is carried out. The goal of this project is to rely on this notion of model and the reflections generated in philosophy and science studies to clarify the bioethics issues raised by the uses of embryo models and formulate recommendations on the regulation.

The philosophical analysis relies on several conceptual frameworks: the philosophy of biology and the philosophy of models, the latter being located halfway between the philosophy of science and the philosophy of technology. The general method is conceptual analysis, discussion of theses and arguments in the philosophy of science literature, and study of the applicability of these theses and arguments to embryo models. In an approach inspired by philosophy of science in practice, we will also draw on empirical elements from interactions with scientists and laboratory visits. The status and role of models in science have given rise to an abundant literature in the philosophy of science in recent years, particularly in the physical sciences but not only: Does the construction of the models reflect theoretical biases? What is a “good” model? What does the model teach us about the reality that it models and under what conditions can we transfer the knowledge generated by the study of the model to knowledge about the “real world”?

The objective is to build upon these reflections (for more details, see below “methodology”) in order to propose an innovative conceptual framework that will enable us, in turn, to formulate practical recommendations in line with the actual properties of models in the lab. The first outcome is an article in philosophy of science that applies the discussion on the conceptual framework of modeling to embryo models. The second outcome is an article in bioethics that bridges the gap between the insights the epistemological analysis provides and the moral status of stem cell based embryo models.