Sarwar Ahmed

For various reasons, it has become common wisdom in science that there exists a principled epistemic distinction between direct and indirect observation. In this paper, I present a twofold argument. First, I argue against such a principled epistemic distinction. Second, I highlight a pervasive incongruence between the methodological and epistemological distinctions between direct and indirect observations. My arguments revolve around the idea that it is one thing to make a methodological distinction between observations and another to ascribe epistemic significance to them. I begin by unfolding the historical and philosophical foundations of the distinction, identifying three tenets that have served to sustain the distinction to the present day. I then provide a detailed analysis of two recent philosophical efforts to preserve the epistemic distinction in astrophysics and specific areas of astrophysics, ultimately suggesting that these approaches face significant challenges.

It has been argued that, in scientific observations, the theory of the observed source should not be involved in the observation process to avoid circular reasoning and ensure reliable inferences. However, the issue of underdetermination of the source has been largely overlooked. I argue that concerns about circularity in inferring the source stem from the hypothetico-deductive (H-D) method. The epistemic threat, if any, arises not from the theory-laden nature of observation but from the underdetermination of the source by the data, since the data could be explained by proposing incompatible sources for it. Overcoming this underdetermination is key to reliably inferring the source. I propose a bidirectional version of inference to the only explanation as a methodological framework that addresses this challenge while circumventing concerns about theory-ladenness. Nevertheless, fully justifying the viability of the background theoretical framework and its accurate description of the source requires a broader conception of evidence. To this end, I argue that integrating meta empirical assessment into inference to the only explanation offers a promising strategy, extending the concept of evidence in a justifiable manner.