To enable microbial colonisation of the gut mucosa, the intestinal immune system must not only react to danger signals but also recognize cues that indicate safety. Safety recognition, paradoxically, is mediated by the same environmental sensors that are involved in signalling danger. Indeed, in addition to their well established role in inducing inflammation in response to stress signals, pattern recognition receptors (PRRs) and a variety of metabolic sensors also promote gut-microbiota symbiosis by responding to "microbial symbiosis factors", "resolution-associated molecular patterns", (...) markers of energy extraction and other signals indicating the absence of pathogenic infection and tissue damage. Here we focus on how the paradoxical role of immune receptors and other environmental sensors define the microbiota signature of the individual. (shrink)

In this paper I discuss the nature of halakhic facts and I frame the discussion in a broader meta-ethical context. Most of the existing literature on the philosophy of halakha has focused on the contrast between ‘Halakhic Realism’ and ‘Halakhic Nominalism’. This theoretical contrast is vague and includes a wide range of theories. Inspired by the meta-ethical literature, I propose to focus the discussion on views that can be called ‘Halakhic Naturalism’ and ‘Halakhic Non-naturalism’. I present, develop and distinguish between (...) different meanings of 'naturalism' and consider arguments for and against 'Halakhic Naturalism'. The purpose of this paper is twofold: First, to present and demonstrate the fruitful encounter between meta-ethics and the philosophy of halakha. Second, to present, evaluate and promote the substantive discussion of naturalistic and non-naturalistic views. (shrink)

Halakha consists of a variety of laws that determine the halakhic status of various actions. Halakhic laws, by their very nature, have a general aspect in that they apply to all similar actions under similar conditions. In this paper, I examine, from a philosophical-analytical point of view, the relationship between the general aspect of the halakhic laws and the fact that these laws apply to particular actions. After the introduction, this paper is divided into three parts. First, I distinguish between (...) two competing theses regarding the "metaphysical order" between the general aspect of halakhic law and its individual cases. The first one, I call 'Halakhic Generalism', according to which the general aspect of Halakhic law has essential precedence. The second one I refer to as 'Halakhic Particularism', according to which the general aspect of the halakhic law is nothing more than a generalization of all its individual cases. In the second part of the paper, I argue that the particularist position has the power to justify a unique and puzzling halakhic principle. According to this principle, in cases of normative over-determination where the same action is forbidden due to two different halakhic laws, then "a prohibition does not apply to a prohibition". Finally, I compare the reasoning I offer for this principle to alternative justifications of said principle. I argue that, compared to the alternatives, the particularist position provides the best explanation for the principle. (shrink)