Anthropological interests on the part of philosophers can be explained on different levels. Since thinking in general is reflective, philosophical thinkers must naturally be interested in understanding the nature of humans, which they themselves are, including the nature of their own thinking. But non-philosophical theorists can also be reflective enough to seek an understanding of human nature and the nature of their characteristic thinking. On a deeper level, with their realization that cognitive functions including philosophical thinking are characteristically human, philosophers may come to reflect upon how such functions are conditioned by human conditions. But such conditions can be addressed by empirical sciences as well, sometimes with greater methodological care or seriousness than can be found among some philosophers, as in cognitive psychology or cultural anthropology. If, in the course of the development of philosophy as a discipline, human experience becomes the primary thematic domain of philosophy, anthropological points must be expected to be found among the results of philosophical research. While philosophers may claim to have a unique aim and method in their investigation of human experience, it by no means is a topic unique to philosophy. There is a practical reason for the anthropological interest on the part of philosophers as well. The field of human experiences upon which philosophers reflect includes the pursuit of values and awareness of norms of behavior. Not only are the nature and sources of values and norms engaging objects of understanding in themselves but their critical assessment must be felt existentially pressing because humans cannot but pursue some values and follow some norms and they have interest in being assured that the values they pursue and the norms they follow are worthy of pursuit and conformance respectively. Even if the sources of values and norms may come to be thought to transcend human nature, as in theological ethics, such determination cannot be made without an examination of human nature as their possible source. But what aspects of human life are relevant here and how they are to be investigated remains an open question. It will be dogmatic to deny that the relevant aspects include some that are fit for empirical inquiry. In light of the fact that common sense, natural and social sciences, history, and religion all have their say about human nature and human phenomena, the following question becomes pressing: Is philosophical anthropology, specifically philosophical inquiry about humans, possible, and, if so, how? This is a necessary philosophical question because philosophy, which aspires to being the maximally reflective discipline, should determine its nature and the above question is a part of its self-determination. Different answers must be expected from diverse conceptions of philosophy. Empiricists would deny, while rationalists would affirm, that there is uniquely philosophical knowledge of humans. All seventeenth and eighteenth century philosophers offered theories of human nature. Some empiricists even called philosophy the theory of human nature. But their philosophical theory only anticipated empirical sciences of human phenomena yet to develop and eventually to supersede it as their own epistemological principles should have persuaded them to admit. Given that the rationalists' project was to construct a comprehensive speculative theory of the real, a theory about humans had to be one of its essential parts. The epistemological principle of rationalism that human reason is adequate for knowledge of the fundamental structure and constitution of reality implies that humans are beings in possession of the rational faculty. Descartes' dualism, Spinoza's monism, and Leibniz's monadism share them and accommodate them in their several attempts to account for the non-rational features of human nature. Philosophy, the highest achievement of reason, and it alone, can offer knowledge of human nature. Anthropology in the strict sense of the designation, on their view, must be philosophical. But it is not the attribution of reason to humans but a further interpretation of reason that makes rationalist anthropology distinct. The rationalists' special interpretation of reason is expressed by their claim that reason is the human essence. This claim implies, among other things, that reason is the dominant faculty, hence that human rationality explains not only human cognition but also the functions of other human faculties, notably, volition, desire and feeling. Even with the admission of the cognitive authority of reason, a faculty other than reason, will, for instance, can be given ontological primacy as in Schopenhauer and Nietzsche, according to whom will is the principle that explains even reason's functions. Human reason, while claiming its cognitive authority, can consistently admit its own vulnerability, even its subservience. Rationalist essentialism cannot therefore be solely based on the view that reason is the cognitive faculty. A theory of human nature even of a rationalist variety requires a further interpretation of human phenomena in which the powers of reason relative to other human faculties are empirically assessed. Since there were no sufficiently developed empirical sciences of human phenomena for the rationalists to contend with, they freely formed views about human phenomena that later empirical sciences would claim a special right to investigate. Rationalist anthropology can by no means be completely speculative. And it is suspect insofar as it includes metaphysical claims of transcendent sort. The turn of philosophy, with Kant, toward theory of human experience heightened the anticipation of a new philosophical perspective on human nature. But such anticipation met frustration. Transcendental philosophy by no means offers a uniform methodology or content. Kant's Critical Philosophy, its classic form, holds that conditions in the subject make experience of objects and the objects themselves possible. But the Critical Philosophy only yields an ambiguous ontological result. The transcendental consciousness in which the a priori conditions of experience reside and operate is not itself a phenomenon in the spatial, temporal and causal system that is constructed in and by it. The subject of this consciousness is itself a product of the syntheses that construct the object: the manifolds of sense intuition are brought to objective synthesis, as Kant says, to the unity of apperception. While he really has no right even to view the transcendental subject as an entity, even as a problematic one, he in constructing his ethics comes to think it, though he disclaims knowledge of it, as a being with rational will and freedom. He offers no straightforward answer to the question "What is a human being?". Human beings that, as we ordinarily believe, exist in nature, history and culture are for him objects of empirical knowledge only; the nature of the subjects that know objects or the moral agents that act in the world of objects cannot be human. Neither natural nor cultural conditions can enter into Kant's explanation of the possibility of human experience or action. The fact that Kant himself offers no definite philosophical anthropology weakens his critique of non-philosophical inquiries about humans, be they metaphysical or empirical. Husserl's phenomenology, though he calls it transcendental idealism, differs from Kant's version. While Kant reasons to the conditions of the possibility of human experience by metaphysical expositions or deductions, Husserl, eschewing such theoretical explanations, aims at describing the essential structures of experience that he thinks can be intuited by reflection from a point of view made possible by a methodological operation, epoche, suspension of the natural standpoint from which the experiences were lived. The methodological operation, however, turns out not to be that innocent: reflection subsequent to it, he believes, discloses that the subject of reflection is a pure ego having intentionalities as its exclusive properties. Humans' being in nature, culture and history, to be sure, becomes an object of phenomenological explication and constitution but its actuality falls outside the phenomenological problematic. Accordingly, inquiries about humans and human phenomena, be they metaphysical or empirical, become objects of phenomenological critique but phenomenology cannot incorporate their findings into the content of its own theory of human nature. Phenomenology consequently fails to offer a full enough answer to the question what it is to be human. The transcendental spirit of inquiry into the conditions of the possibility of human experience or its essential structures should have further led to an even more fundamental question how philosophical thinking itself is possible. Transcendental philosophy neglects to address it. A transcendental stance is taken under two disputable assumptions: (1) that it is the absolute limit of reflection, not conditioned by anything; (2) that reflection from it alone can establish necessary and strictly universal truths about human experience. The first assumption may come from the fact that introspection upon thinking does not disclose conditions, natural or cultural, that affect it. The subjectively confirmed transparency and autonomy of thinking, however, is not sufficient evidence that establishes them. Two sorts of presuppositions can be distinguished, the beliefs that one explicitly takes to be the basic internal principles of his or her system, and the beliefs about the conditions that explain the possibility of one's own thinking. Subjective removal or suspension of presuppositions of the second kind has no consequence on either the existence or nature of conditions of its own possibility. Furthermore, the allegedly necessary and strictly universal principles of experience, as a matter of historical fact, are subject to refutation or revision in the continuing philosophical discourse. Transcendental theories of experience themselves belong within an intellectual history among theories of the same that arise, enjoy credence awhile, and wane. The radicalness of reflection is misunderstood by the transcendental theorists to be achieved by a willful removal or suspension of its presuppositions as if such mental operation can magically render their thinking pure and unconditioned. Thinking can become truly radical only by minding the conditions of its own possibility. Some of them may be hidden from immediate reflection and no certain knowledge of them may be forthcoming even if they are to be disclosed. The difficulty of addressing such conditions is exemplified by the fact that the suspicion about the influence on philosophical thinking of the thinker's social situation, gender and ethnicity is only a recent emergence. The quest for certainty that motivates a transcendental turn defeats the mission of thinking to explain itself. Despite his claim that he is not a humanist but an ontologist, Heidegger's ontology attempts to ground a new form of philosophical anthropology. He invents a new language, a new conceptual scheme, and a new method for understanding being human. His rationale for making this move is that being human is already understood by humans (a disputable claim) and that the mission of philosophy is to explicate this implicit understanding by interpreting it out of lived human experiences. Part of his hermeneutical strategy is correcting the distortions of that pre-understanding wrought by theories including, especially, past ontologies. The core of such distortions for him is the concealment of the being of humans. "The being of humans" signifies a structure of possibilities of beingmodes of existence that humans have freedom to choose. Such possibilities for him should be understood, not explained by a science or sciences that objectively describe and explain properties given to things. Heidegger thus attempts to reclaim the uniqueness and autonomy of a philosophical inquiry about humans. I shall make only one critical point that I consider especially relevant in the present context. Freedom and the other existentialia he speaks of are matters of subjective confirmation. Freedom so confirmed does not imply that the ontic human phenomena that, as he insists, should only be understood, interpreted and explicated cannot also be explained. An ontic human phenomenon is amenable to explanation by objective conditions that may even escape one's awareness. Explanatory theories of human phenomena are possible. And humans have as much need for explanation as their need for understanding. Their need for explanation is especially strong when the phenomenon is puzzling, beyond understanding, like the Holocaust, the Great Depression, or the collapse of the Soviet Empire. A philosophical ontology should offer foundations for explanatory theories, with an account of the complementary relationship between understanding and explanation. There is the position that the job of philosophy is not to produce substantive knowledge of anything but only to offer conceptual analysis and/or an epistemological and methodological critique of substantive inquiries about it, hence that there is no philosophical anthropology if it is to be an activity productive of specifically philosophical knowledge of the human. The designation "philosophical anthropology" on this view is a misnomer for an epistemological/methodological critique of substantive inquiries about the human. This position, taken by logical empiricism and its offshoots, traces to empiricist origins; it is a negative reaction against both speculative and transcendental philosophy. The issue here is whether the position is fully intelligible without an ontological commitment of its own. In fact, it carries a commitment to the naturalistic thesis that humans are embodied entities existing among and interacting with other entities in nature. If philosophy is to be radically critical, it should address the presuppositions of the theory it examines as well as bare and justify its own in so doing. While transcendental philosophers dogmatically deny presuppositions of their "transcendental activity," analysts/critics tend to avoid addressing theirs. This propensity may come from their reluctance to engage in a dispute about naturalism which they suspect to be metaphysical. But if philosophical thinking is to be radical, it should make explicit and justify its own presuppositions even if doing so may force a reconsideration of its own definition and its prior principles. Philosophy undeniably affects the way of understanding human nature, at least by its conceptions of itself and other inquiries and the methodologies it recommends. This does not necessarily imply that there is substantive knowledge of human nature that is uniquely philosophical. The issue of the nature and possibility of philosophical anthropology can thus be addressed only through an examination of philosophy's self-conception. A compelling presupposition of philosophical thinking is that the subject of such thinking is a human being in the uncomplicated sense that it is a being in nature with its biological destiny, that its psychic life including philosophical thinking has a physical basecompelling in that none of its contraries recommend themselves over it at this juncture of the history of human knowledge. Though a physical explanation of human psychic phenomena is the most difficult kind actually to produce, relevant sciences not being fully developed, the possibility of such explanation should be presupposed. This, however, should not mean that philosophical thinking should stay paralyzed until a physical explanation of itself becomes available. It has cultural conditions by which to explain itself. If nature makes philosophical thinking, any thinking, possible, it does so through the mediation of cultural conditions such as the language it uses, existing beliefs and theories it incorporates into itself, philosophical or otherwise, and the institutions, practices, and interests that regiment or influence it. Since cultural conditions are understandable, verständlich, an explanation of philosophical thinking by them is more illuminating than a reductive physical one. Philosophical thinking should have a twofold relationship to such conditions: it should understand them as well as explain how they affect it. Maintenance of this relationship is complex and difficult. The language of philosophy not only serves as its instrument but also shapes it. Because language is so proximate to philosophical thinking, it eludes and resists thematization. The lateness of the rise of philosophical interest in philosophical language attests to this. And the boundary between philosophy and non-philosophy needs radical rethinking. Views and theories of non-philosophical origins assimilate to philosophical consciousness and many of them become unproblematic premises of philosophical reasoning. History belies the picture of philosophers ever keeping critical distance from views of non-philosophical origins or deigning to accept them only after a thorough critical evaluation of them exclusively by principles internal to philosophy. The fusion of theology with philosophy in the Middle Ages or the increasing penetration of scientific methods, themes and theories into contemporary philosophy should support the view that philosophy is a porous and changeable practice among such practices in a field of ideas having mutual affinity. Even the dialectical relationship of philosophers with views they oppose, be they of philosophical or non-philosophical origins, contributes to the determination of their stance. Philosophy, like any other human cultural activity, is in part a creative construction and in part a use of what is made already available by surrounding culture. Exclusive emphasis on its creativity or its receptivity distorts its actual character and historical career. Insofar as philosophy absorbs non-philosophical views of human nature and human phenomena, with or without full critical assessment, it already participates in a continuous human reflection on the human with an ever determinable structure where the boundaries among the conventional disciplines are not sacrosanct. The striking variety of conceptions of philosophy is partly explainable by different influences from outside philosophy. The juxtaposition and comparison of, for instance, the views of Aristotle, Aquinas, Descartes, Hume, Kant, Marx and Nietzsche on human nature should make us despair of finding a philosophical essence of anthropological views. The distinct contribution that philosophy as a discipline can make to the understanding of humans is not so much special content or even a method as its ethos of valuing critical thinking and integration of human knowledge. Philosophical anthropology, as a special area of a unique discipline, should be held suspect. There only is a dimension to each inquiry where many, if not all, of the questions philosophers raise are significant. The mission of philosophy is to make all human inquiries, including the anthropological, maximally reflective in the given cultural situation.