Why does "theory-ladeness" of observation present a problem for inductivism?
A second area of difficulty for the inductivist lies in the distinction between observational evidence and
the theories it is used to support. The inductivist program depends crucially on a sharp distinction between
"observation" and "theory": the observations are the evidence for the theory, the truth of the general
statements of laws and theories is alleged to follow inductively from the truth of observation statements.
The problem lies in the fact that with this approach we are supposed to start the scientific method with
a direct verification of observation statements, and then, after observations are made, we infer the
theoretical laws. However, without any prior theoretical belief, there is no particular observational
question to ask; without some sort of conceptual "framework", there is no language to report the
observation in. Any real observational state of affairs can be described in a potentially infinite number
of different ways. Without any theoretical belief there is no guidance as to which of these manifold
observations to make. We call the argument that theory must precede observation the argument for the
"theory-ladeness" of observation. If its conclusion is correct, how can justification begin with observation
statements as inductivists maintain?
For these reasons, many defenders of the empiricist consensus rejected inductivism in favor
of a hypothetico-deductive or "H-D" model of justification of laws and theories.