Precision medicine and diseases as natural kinds: An epistemological dilemma.

Background: The most important advance of precision medicine (PM) has been a specific way to define and understand disease. However, PM may fail to be therapeutically effective if diseases are natural kinds.

Objective: To attest adverse consequences of treatments suggested by PM that do not generalize well.

Meaning and Affect in the Placebo Effect.

This article presents and defends an integrated view of the placebo effect, termed "affective-meaning-making" model, which draws from theoretical reflection, clinical outcomes, and neurophysiological findings. We consider the theoretical limitations of those proposals associated with the "meaning view" on the placebo effect which (a) leave the general aspects of meaning unspecified, (b) fail to analyze fully the role of emotions and affect, and (c) establish no clear connection between the theoretical, physiological, and psychological aspects of the effect. We point out that a promising way to overcome these limitations is given by grounding the placebo effect on Peirce's theory of meaning, in which the role of the meaning constitution and change is placed in logical and objective structures.

Peirce on the justification of abduction.

What sort of justification can be claimed for abduction? In this paper we reconstruct Peirce's answer to this question. We show that in his early works on the logic of science Peirce provided an abductive justification of abduction, and that in his mature writings the early solution is enriched by a reference to the place abduction has in a typical scientific inquiry. Since abduction is the first stage of inquiry by which a hypothesis is suggested and which then has to be subjected to inductive testing, the fundamental abduction (ur-abduction) that justifies abduction has also to be subjected to a verification by means of a fundamental induction (ur-induction), namely that the abduction that abduction is valid is verified by an appeal to the history of science.