As previously promised, I would like to say a word or two about my claim that Heidegger can be read as a Realist Historicist. My conception of Realist Historicism is drawn from Heidegger's early engagements with the problem of the origin of concepts and meaning. Rather than explain in detail what I take Realist Historicism to be and what its origins are, both explanations I present at length elsewhere, I will allow my discussion of realism and historicism generally to make clear the outlines of my own position.Let me say first that there are absolutely legitimate reasons to be wary of calling Heidegger a historicist or realist. Heidegger follows his teacher Husserl in explicitly rejecting historicism. He is also very clear about his rejection of the idealism/realism debate, although he spends more time rejecting idealism than realism. The reason he rejects talk of idealism and realism, and one of the reasons he rejects historicism, is because all three theoretical positions are based upon the understanding of humanity as minds relating to objects. Insofar as Heidegger rejects mentalism and the subjectivism which he claims is inherent in the subject/object epistemic view of the human condition, he also rejects the theoretical positions that grow out of it. I do not dispute any of this, rather it is at the heart of my conception of realist historicism. Despite this fact, however, it is not at all unusual to find Heidegger discussed as a Linguistic Idealist, Transcendental Idealist or Transcendental Historicist. It is largely in contrast with these positions that I have developed my discussion of Realist Historicism. Insofar as I agree with the rejection of the subject/object distinction in understanding Heidegger it would be inadequate to call Heidegger just a realist or just a historicist. The conjunction of elements of the two positions creates, I believe, a third position that is not subjectivist or dependent upon a subject/object model. Let me make clear how this is so through an attempt to define the key terms in this discussion. In each case I will offer a traditional definition, the Realist Historicist definition and at the end I will explain the added element which unites the individually incomplete conceptions of realism and historicism to form the unified position.
Traditional Historicism: The view that (1) all human knowledge is historical in nature and structured-by/relative-to the historical era in which it is found and (2) historical eras are disjunctive and unconnected. Comment: This view is a form of dogmatism and amounts to a seemingly self-contradictory claim that we can have no a-historical knowledge except for the dogmatic assertion that knowledge is relative to historical eras and historical eras are independent of each other.
Historicism in Realist Historicism: The view that (1) all human knowledge as far as we can tell and based on what we have reason to believe is structured-by/relative-to the historical era in which it occurs, (2) as of now we have no reason to believe that we have access to a-historical knowledge that would apply to all historical eras and (3) it is as possible for eras to be disjunctive as conjunctive but we have no reason to think that it is necessary or universally the case that eras share elements. Comment: This position is a form of limited skepticism, specifically a Hermeneutic skepticism which finds no reason to believe that a-historical knowledge is possible and finds no model or conception of what such knowledge would be like.
Traditional Realism: The view that (1) there is an unchanging reality independent of the human mind (Ontological Realism) and/or (2) we are able to have access to this reality (Epistemic Realism). Comment: This position is only meaningful through reference to the divide between the human mind and what is outside of that mind, even when the goal is to show that the divide can be bridged.
Realism in Realist Historicism: The view that (1) what is presumed in traditional realism to be mental or subjective arises from Reality and so there is no "mind" or "consciousness" independent from Reality. (This is captured in Heidegger's insistence that the problems of modern epistemology are, generally, theoretical conceits and distortions. Since the being investigating reality is part of the being under investigation there is no gap to be overcome.) This ontological claim, reversing ontological realism, goes together with another ontological claim relating to epistemic realism. Specifically (2) all disclosure is disclosure of Reality, so we can know Reality, but (3) all disclosure is finite, so we never know all of Reality. In other words, Reality is always more than what we have actually said or thought of it at any given time ("Language is the language of Being, as clouds are the clouds of the sky." Heidegger "The Letter on Humanism"). This may, but need not, mean that Reality is independent at points from language or human practice (if the phrase "at points" is even meaningful in this context). We can't, however, say what this this would mean even as we can't say what history without time, or Dasein without history, would mean even though the skepticism we encountered in our discussion of historicism requires us to admit such things may be possible if not imaginable.
The Added Element: As I mentioned earlier, I believe that the new definitions of both historicism and realism are incomplete without the other. Specifically, our definition of historicism leaves undetermined what it means for something to be "historical" or why/how something can be "relative to a historical era". Similarly, our definition of realism fails to address what realism actually looks like when we have taken out those problematic terms "mind", "consciousness" or "subjectivity" which is necessary if realism is to have any meaning in a Heideggerian context. The completion of both definitions rests in an understanding of practices as the being of history and the being of the investigating entity which is mistakenly thought of as mind divided from reality. This shows up, for example, in Heidegger's conception of historicity i.e. the way in which humans are a carrying forward of inheritances and a projecting of these into the future so that things come to disclosure as meaningful within the "light" of the inherited project. History is made possible by these ongoing temporal events which, for short, we could call practices.
Realist Historicism: The view that (1) as far as we can tell and based on what we have reason to believe everything we know or experience shows up within human practices. Indeed, it is unclear what something would be without the mediation of practices. This is also the case for "subjectivity" or the "mind". This leads to two possible conclusions (2) either Reality just is ongoing practices or gives rise to practices as its mode of appearance. (As a side note, this allows for two types of Realist Historicism. There is what I sometimes call Practice Ontology which holds to the first option, and Heidegger's position which holds to the second as I shall discuss.) Heidegger's belief in origins and originary events (Ereignis) suggests that he held the second view since originary events arise independent of previously existing practices. In other words, the event ontology which is Heidegger's brand of Realist Historicism allows for two distinct types of events. Practices (i.e. ongoing events with origins) and Originary Events from which practices take their origin. The addition of practices as the ontological ground of our previous discussion of realism and historicism is clarified by a distinct characteristic of practices which ties into Heidegger's teleological world-holism. Specifically, practices are like words in that the existence of one word requires the existence of many words. This leads to the claim that (3) practices (as far as we have reason to believe) are interconnected and interdependent. Similarly, the temporal nature of practices means they (4) are historical and indeed, as Heidegger argues, the ontological ground of history.
When one combines 1, 3, and 4 from above one sees clearly that everything we know or experience depends upon the total complex of practices within which it arises and this complex is historical (i.e. temporally changing and tied to the coming-to-be and passing-away of practices and/or Originary Events in the past). This is Historicism. When one combines 1 and 2 we get our Realism.