 The rise of naturalized epistemology as a movement within analytic philosophy in the second half of the 20th Century has largely sidelined the rationalist style of approach. From the naturalistic perspective, philosophy is conceived of as continuous with science, and not as having some independently privileged status. The perspective of the naturalistic philosopher may be broader, but her concerns and methods are not fundamentally different from those of the scientist. The conclusion is that science neither needs—nor can legitimately be given—external philosophical justification. It is against this broadly naturalistic background that some philosophers have sought to provide an epistemic justification of simplicity principles, and in particular principles of ontological parsimony such as Occam’s Razor.