The analytic philosophy of logical positivism or logical empiricism, which dominated 20th-century Anglo-American scientific thinking, leaves philosophy with a complex and problematic legacy that must be addressed and overcome if we are to have any hope of a renewed, meaningful, philosophically rational realism.
On the one hand, the positivist view of philosophy is deflationary, diminishing and even de-legitimizing the very notion of philosophy. The idea that philosophy was to become 'underlaborer to science', following Lockean empiricism, proved quite popular with scientists and science enthusiasts, and to this day informs the common belief that philosophy can be wholly displaced by empirical investigation on pretty much any question. On the other hand, following the linguistic turn and Thomas Kuhn's historicist account of science, many disillusioned analytical philosophers have become convinced that their discipline cannot really provide any affirmative, unchanging, principal foundations to scientific thinking. For example, the principles of method and observational verification sounded great until one realized that the principles themselves couldn't be reached by method nor verified by an empirical observation.
The problem we're given here is that despite the serious challenges to Whiggish science triumphalism recognized by Kuhnian history of science, the latter has produced only criticisms but no affirmative solutions, and the philosophical tenets of logical positivism continue in fact to provide the ideological and normative principals which inform much thinking about science in the public sphere. So philosophy is still widely granted some limited importance as a form of critical defense by non-positivistic and humanistic areas of thought, but the influence of logical positivism remains strong. It is evident everywhere someone asserts in the public sphere that empirical investigation functions (in fact or potentially) wholly independently of philosophical considerations.
For example, we often see the positivistic attitude in the 'God debates' by enthusiasts of the New Atheism. Sam Harris has said that 'what we now know in neuroscience shows that there is no free will'. In such statements we can detect the thrill Harris must get from making a big, threatening, macho statement presumably resounding from the bowels of deep science out towards the unscientific public with their silly myths and folk beliefs. This is the sort of attitude the legacy of positivism continues to leave us with. It is clear here that Harris is either philosophically ignorant or uninterested in questioning his own concept of free will, where it derives from, or the question of how it is possible in the first place that a conflict between concept and reality could arise at all. Positivism prevents intelligence from recognizing itself. It is an incredible irony and a mark of philosophical shallowness that Harris and his followers claim the banner of 'reason' when their positivism operates with a diminished, instrumental, utilitarian sense of 'reason' that is in conflict with their claim to realism.
Check out this site to see the influential metaphysical picture of reality that is the legacy of logical positivism.