pragmatism, and experimental method
Peirce's method of categorial development
reveals the experimental nature of phenomenology, of metaphysics, and
of the relation between their respective claims. The phenomenological
categories of Firstness, Secondness, and Thirdness come to light as an
interrelated set of meanings, abductively generated as a tool for focusing
on the richness of experience in order to elicit its illusive, "intangible"
but pervasive textures, "traits" "tones or tints". The move from experiential
claims to metaphysical claims is an imaginative extension via analogy.
In the development of his metaphysical categories, there is an exaggeration
of the experimental method by which we have meaningful everyday experience.
There is an exaggeration of the metaphorical, imaginative, creative features
of the meanings which arise out of past experience though abductive fixations
of experience, and which legislate for the analysis of future experience.
Further, there is an exaggerated attentiveness to what appears in experience,
to its pervasive features or textures, an attentiveness which both founds
the categories and serves to verify their adequacy. The claims of his
experimental phenomenology, and hence the claims of the metaphysics which
it grounds, are fallibilistic and open to alternative categorial possibilities.
It is generally held that Peirce's philosophy incorporates diverse methods for obtaining the categories, a priori deduction from mathematical principles and phenomenological inquiry. This diversity has been explained in several ways, such as a manifestation of different systems chronologically developed,  or a conflict between naturalist and transcendentalist strains of his thought.  From the present perspective, however, one method, the phenomenological method, is at work in Peirce's derivation of the categories--though he of course did not use this term until late in his career--and there is a distinctively pragmatic character in its dynamics which involves both fallibilism and an implicit pluralism. This view of Peirce's phenomenology in turn has significance for interpreting his understanding of the nature of the metaphysical enterprise and the dynamics of its relation to his phenomenology.
The phenomenology Peirce develops could be called hermeneutical phenomenology, but perhaps, in the context of his pragmatism, experimental phenomenology is a more appropriate label, and one which points more directly to its key pragmatic features. From this perspective, Peirce's categories of Firstness, Secondness, and Thirdness come to light as an interrelated set of meanings, abductively generated as a tool for focusing on the richness of experience in order to elicit its illusive, "intangible" but pervasive textures, "traits" "tones or tints".
It is important to distinguish the abductive, creative genesis within experience of the categories, their logical priority for the future delineation of experience, and the verification of the adequacy of their application in the ongoing course of experience. These experimental dynamics come into focus by examining in just what sense Peirce's phenomenology "simply scrutinizes the direct appearances" or confines itself to "honest, single-minded observation of the appearances." First, it involves "pure observation" in the sense that it does not make judgments concerning the reality of what is observed. It is the the description of the phaneron, understood as the "collective total" of all that is present to awareness irrespective of whether or not it corresponds to anything real.  In this sense, it is concerned with phenomena in their dimension of Firstness.
When Peirce claims that his phenomenological derivation of the categories is an experiential derivation, he is taking experience in its broadest sense, and to include not only experience of the real world but experience of ideal worlds, of illusion, etc., and includes interpretations as well as matters of sense. Thus experience in the context of Peirce's phenomenology cannot be understood in the more restricted Peircean sense in which "the world of experience" is equated with "the world of fact". Phenomenology involves pure observation, then, in that it observes the entire range of experience, possible and actual, without judgments of objectivity.
Phenomenology is further concerned with the observation of appearances in that it does not impose upon the experiences the frameworks of any of the sciences. It is in this sense that one needs the ability to see what presents itself, just as it is, needs "the observational powers of the artist."  Yet, though phenomenology is pure observation in the above two senses, there is, for Peirce, no observation without the directing focus of meanings. He emphasizes that the "matter of sense" is a hypothetical something that cannot be grasped as such independently of interpretation.  Phenomenology, for Peirce, consists strictly in the observation and classification of whatever seems to be before the mind at any given time. It provides the ultimate analysis of experience, but in order to classify and analyze, there must first be the creative formation of meaningful structures which provide the delineations for classifications and the tools of analysis. Interpretive, legislative elements must enter into the phenomenological focus on experience as it appears in order for an "observing" mind to grasp and delineate its pervasive textures. The creative mind both adds to and organizes these "hints of sense", making them precise and intelligible. 
Within the context of Peirce's radical rejection of the spectator theory of knowledge it is not possible to focus on any aspect of experience independently of interpretive elements, and there are highly interpretive elements at work in Peirce's phenomenology as the "pure observation" of what appears as it appears.
Conversely, there are experiential elements involved in his so called transcendental strain or his "logical deduction" of the categories. Here, as elsewhere, Peirce's Kantianism is a radically transformed pragmatic version, and it rules out both intuitionism and formalism.
Peirce points out that since Kant the importance of systems being constructed architectonically has been recognized, yet, the full significance of this has not been adequately apprehended.  He offers a critique of past philosophical systems which take an interesting, fruitful idea, adopt and develop it and then force all kinds of phenomena into its structure to provide explanation. Peirce's specific recommendation for those who wish to form an opinion about fundamental problems of philosophy is that they examine all areas of human knowledge so that they understand the nature of the materials a philosophical theory must concern itself with, and only then turn to the nature of philosophical problems and the best way of solving them.  And, his point concerning this type of empirical survey is geared toward the specific recommendation that one engage in a systematic study of the conceptions and their interrelation and uses which are capable of building a good philosophic theory. 
After looking at many different disciplines and giving a brief "hint at their nature" in providing conceptions "serviceable for philosophy", Peirce turns to the examination of logic and finds analogous conceptions. Any phenomenological survey must include a phenomenological examination of logic, for as Peirce holds that phenomenology is concerned with the "kind of constituents in our thoughts and lives" taking thoughts in the logical, not in the psychological sense.  He finds that three conceptions are consistenty found in every theory of logic, though these conceptions, being broad and indefinite, are hard to grasp and easily ignored. And, recognizing the tentative and vague nature of the experiences which give rise to the abductive generation of the categories, encourages future students to retrace his path and present their results. 
Only in light of such a vague, and empirically grasped recognition of these distinct conceptions can Peirce abductively create the interpretive structure which allows him to claim that "We find then a priori that there are three categories of undecomposable elements to be expected in the phaneron".  This is not a Kantian fixed a priori, but rather this claim is "a priori" in that although it is abductively generated in the light of past experience it is logically prior to the analysis of ongoing experience. It is a tool created to bring to experience for the interpretation of experience, one which can be discarded for another if it does not adequately work, and which is thus like the conditional or hypothetical certitudes of mathematics. The tool dictates what we must find if we use it; if we use it, then certain things must follow, for it legislates for the interpretation of experience. But, it may be found pragmatically useless in that too much of experience cannot be incorporated into it. Thus, after asserting the "a priori" nature of the categories, Peirce is led immediately to suggest, that one turn to the phaneron, as each of the categories has to find its justification in its usefulness within experience.  They cannot be regarded as final "as Kant thought" but must be put to the test by an independent examination of the facts. 
Peirce, then, can emphatically point out the uselessness of transcendentalism  yet hold to an a priori dimension in the formulation of the categories, for there is a dimension which legislates the manner in which we focus on experience. Like all interpretive tools, the categories of phenomenology arise out of experience but in turn are legislative for the analysis of experience. They are neither handed down from on high, nor are they pure inductions from experience, but rather are a creative, interpretive framework through which to focus on the entire gamut of "whatever is in any way present to mind". Thus it is that Peirce can claim that with his interactional, synechistic understanding of subjective-objective, the issue of the a priori "gains new life". 
The "a priori" categorial set is not something fixed, final, or absolute. Rather it is a tool which though in being applied is legislative, yet is itself further developed or refined in the very process of legislating, for its adequacy must be continually tested by future observations, and it must allow for predictions to be tested by future observations.  These new situations both serve to verify, and to demand revision of, the categories.
Though Peirces relation to logic is generally held to point toward the "formalist" strain of his thought, yet a brief sketch of its history points toward the ongoing pragmatic, processive, open ended nature of categorial determination developed above. His interest in the interactive relationship among three irreducible conceptions is something he brought to his understanding of logic. Peirce's three categories brought into significant focus in a general sense the new observations involved in examining the logic of relatives, yet were revised because of their inability to adequately deal with this new area under examination. And, there is of course a big difference between revising the categories in light of their inadequacy to accommodate the new data of the logic of relatives and the claim that they are deduced from the logic of relatives.
David Savan points out that Peirce clearly vacillates as to whether to rest logic upon observation or to rest observation upon logical procedures.  What Peirce did not adequately see was that no clear cut answer could be given because of the dynamic interplay between the two. The categories are derived from experience yet legislative for the analysis of experience, while at the same time subject to revision in light of experience. These experimental dynamics hold in the area of logic as well as in all other areas of experience. Developments in any area of human experience are brought into focus through the categories, but may themselves demand categorial revision. This is not a vicious circle but an exemplification of the cumulative process involved in the pragmatic, experimental interplay between meanings and experience.
Phenomenology, precisely as experimental phenomenology, displays this pragmatic interplay. What is involved in the experimental nature of phenomenology is an organization of experience in ways which work in grasping universally pervasive tones or textures of what appears as it appears, tones or textures which are continually put to the test in future observation of phenomena. These categories which work have arisen through the creativity of abductive processes based in part on the thorough study of the various disciplines to obtain a "hint at their nature" and, once developed, can be applied back to these disciplines in forms and terminologies relevant to each, though in their very application they are subject to the test of continual workability.
The failure to recognize Peirce's halting and never clearly defined use of the above method leads to the often raised question as to whether he was attempting an empirical justification of the categories or an a prior deduction of them. If a dichotomy is made in this way, then the problems attributed to Peirce's method do in fact arise. If the method is empirical, then we cannot know that the categories have universal application. Alternately, if the method reduces to a rational assertion, they have universal application "by fiat" but seen somewhat arbitrary in their application to experience.
Thomas Goudge points out that "in reality Peirce's phaneroscopy is a double-edged sword, possessing at once both its rational and empirical edge."  It is precisely Peirce's pragmatic interrelation of "rational" and "empirical" factors in his phenomenology which are incorporated in the dynamic interplay between meanings abductively formulated and legislative for experience, and the vague experiences which give rise to them and which, as made precise through these interpretive or legislative tools, serve to judge them adequate or inadequate.
If, as Peirce holds, the dynamics of experimental method allow for alternative interpretations which are continually open and subject to revision, then he must allow for the possibility of alternatives to the categories of Firstness, Secondness, and Thirdness. This, however, is precisely what he does hold. Peirce nowhere indicates that his categories are absolute or eternal and in fact states quite clearly that though his selection may probably be the most adequate, alternative series of categories are possible.  He holds that his selection is merely is one such set having its own unique importance which is perhaps not greater than that of other sets,  and acknowledges that we contnually meet conceptions which his set does not include,  and that there is perhaps no compelling reason for thinking that his three "universal categories" are more universal than others.  Moreover, pluralistic implications are contained in the fact that Peirce can claim both that his set of categories is probably the most adequate, and also that not only are alternative series of categories possible, but that "at every step" features are met with which do not fit his categories or "series of ideas", for his set does not "comprise" all.  And, since his set may well be the most adequate, but yet does not comprise all, presumably by their very nature categorial sets cannot do so, thus allowing for alternative possibilities. Even the most adequate set of categories will not rule out the possibility of grasping the phenomenon in different ways which work in grasping features which overflow the bounds of those categorial distinctions. It has been seen that what one finds is partially dependent upon what one brings, and alternative ways of bringing will lead to different discriminations within the rich textures of the phenomena. Some ways of discriminating within the phaneron are better than others, but none can be exhaustive of its richness, and other categorial sets may be "equally universal". Peirce's experimental phenomenology, then, is not only fallibilistic, but incorporates an inherent pluralism, for there are in theory always alternative, perhaps equally adequate, perhaps better, ways of organizing the phenomena because of the creative abstractive nature of the categories and the richness of the phaneron.
The discussion thus far has focused on the development of Peirce's categories through a pragmatically oriented "experimental phenomenology". It is now time to turn to an examination of Peirce's move from the categories as phenomenologically descriptive of the textures, tones, or tints of experience to the categories as metaphysically assertive of reality, and to the dynamic experimental nature of this move which both founds the speculative categorial claims of metaphysics and gives further confirmation to the adequacy of the categories as phenomenological.
Peirce holds that "Metaphysics is founded in phenomenology but goes beyond it, taking them to be real constituents of the universe.  But, the move from experiential claim to metaphysical claims is an imaginative extension via analogy. 
For Peirce there is no gap between the categories as phenomenological and as ontological, for there is no gap between experience and reality. What appears within experience, then, is also the appearance of the independently real; there is no ontological gap between appearance and reality. Further, it is at the same time "to me" to whom it appears and reflects my intentional link with the externally real, "just as a rainbow is at once a manifestation both of the sun and of the rain."  For Peirce, these are "two sides of the same shield".  The general features manifest in the phenomenological dimensions of experience and embodied in the categories metaphysics throw us onto the reality within which we are embedded. The categories as metaphysical indicate discernible features which help in understanding the interrelated characteristics of the universe in which we are embedded.
These metaphysical categories involve neither spectator attempts to grasp reality "as it is" independently of our modes of interpreting, nor related attempts to transcend our perspectival condition by a move to an absolute perspective which somehow contains all other perspectives. Rather, they are products of creative, abductive attempts to articulate features of reality in a way which can accommodate the various tones or textures to which we are attuned. Like all interpretive tools, the metaphysical categories are perspectival and subject to revision in terms of their workability in accounting for features of reality which intrude within experience and pervade the tones and textures of experience. Peirce's mode of eliciting the phenomenological categories and his subsequent application of them to metaphysical reality indicates an awareness of this.
While metaphysics is dependent upon phenomenology and hence on the categories phenomenology establishes, yet metaphysical claims concerning the realities represented by its own categories legislate, and must prove adequate for the analysis of, the experience of reality. Further, the adequacy of the metaphysical categories in their own right gives added verification to the categories of phenomenology in which they are grounded. Thus, though metaphysics presupposes phenomenology for its categories, the adequacy of the metaphysical categories, which are verified through the intelligibility they introduce into our experiences of the real, helps verify the adequacy of the phenomenological categories. If the categories are inadequate for metaphysics then they are inadequate for phenomenology, for reality appears in the phenomena, though in focusing on the phenomena it is not judged as reality. Peirce's metaphysical claims, then, are rooted in the phenomenological interpretive descriptions of experience and help verify their adequacy. There is an experimental dynamics operative in the articulation of the phenomenological categories, in the development of the metaphysical categories, and in the relation between the phenomenological and metaphysical categories. The fallibilism and pluralism indicated above in Peirce's "experimental phenomenology" holds mutatis mutandis for the metaphysical context which it founds.
The entire process is a cumulative one based on the pragmatic interplay at every level between concepts or categories and experience. Our interpretive concepts and categories at all levels have arisen out of past experience and have been made prescriptive for the interpretation of future experience. This type of mutual feedback harmonizes quite well with the conception of scientific method as indicating a self-corrective rather than a "building block" enterprise. This leads to the the scientific as well as metaphorical nature of metaphysics.
Peirce holds that the metaphysical endeavor is like that of the special sciences, except that metaphysics depends on a kind of phenomena that so saturates our experience that we usually pay no attention to them.  Thus, the data for metaphysics differs from that of science precisely because the former is so pervasive of our every experience that its presence is often not recognized. This difficulty can be dealt with through the painstaking method of experimental phenomenology which provides, ultimately, a clearer focus on the data from which metaphysics begins.
Peirce observes that the assumption which underlies metaphysics is not so different than the assumption which underlies the possibility of scientific success, for both suggest ways of thinking and depend upon human ways of thinking having a tendency to be like the ways in which the universe acts.  We can understand or even conceive of scientific or metaphysical claims only as in some way analogous to our experience. Humans cannot think anything about what is beyond the limits of experience
Thus, that which transcends experience in either science or metaphysics is an metaphorical in the sense that we can think of it only in terms of our experience. In both science and metaphysics, we proceed to hypothesis via analogy from experience to the conditions which account for it. Both science and metaphysics rest on observation but proceed to explanatory frameworks.
Imaginative, metaphorical thinking is involved in much more than science and metaphysics for Peirce, however, for he stresses that while metaphysics as been disparaged as being a "fabric of metaphors", yet even the conceptions of logical and phaneroscopy are couched in metaphor, as is the very fabric of thought.  In terms of his own metaphor, "a pure idea without metaphor or other significant clothing is an onion without a peel."  Metaphysical thought, like scientific thought, is continuous with the dynamics of common sense perception. The imaginative flight of metaphysics does not form a tension with Peirce's pragmatic theory of meaning, but rather arises from it. As Peirce insists, while the meaning of conceptions lies in conceivable practical effects, this allows for flights of imagination which "alight upon a possible practical effect", and in this way allows for many more hypotheses than one might think at first glance.
Because the data from which metaphysics sets out are the characteristics which pervade all experience, scientific and nonscientific alike, its conclusions must be more comprehensive and hence less verifiable than the conclusions of scientific theory, but the difference is not essentially one of kind.
The difficulty of either formulating or verifying a metaphysical theory does not mean that metaphysical speculation will or should eventually halt.  Nor should it end, for as Peirce takes his stand here, the poetic is not identical with the fictional but rather can convey profound truth;  moreover, there is an intellectual need for metaphysics, for the scientist who claims to get along without metaphysics offers doctrines that are packed with and vitiated by crude and uncriticized metaphysics.
Peirce's metaphysical discussions are couched in highly speculative, metaphorical, and anthropomorphic language not in spite of the nature and limits of meaningfulness imposed by his pragmatic epistemology but because of them. His metaphysical discussion are highly metaphorical precisely because he recognized them to be metaphorical or imaginative extrapolations from experience. As John E. Smith has aptly captured this point, "Peirce was acutely aware both of the extent to which metaphysics involves 'extrapolation' and of the unavoidability of this sort of reasoning if we are not to deceive ourselves concerning the ultimate assumptions behind what we believe."  If on the one hand Peirce's claim to be scientific in his metaphysics is taken too narrowly, or on the other hand his metaphorical assertions are taken too literally, then his doctrines will seem outrageous and often contradictory.
examination has attempted to understand Peirce's pragmatic method, or
method of experimental inquiry, as the context within which his doctrine
of the categories can be interpreted. His method of categorial development
reveals the experimental nature of phenomenology, of metaphysics, and
of the relation between their respective claims. And, one can see in this
development an exaggeration of the experimental method by which we have
meaningful everyday experience. There is an exaggeration of the metaphorical,
imaginative, creative features of the meanings which arise out of past
experience though abductive fixations of experience, and which legislate
for the analysis of future experience. Further, there is an exaggerated
attentiveness to what appears in experience, to its pervasive features
or textures, an attentiveness which both founds the categories and serves
to verify their adequacy. And, as Peirce has been seen to point out, the
claims of his experimental phenomenology, and hence the claims of the
metaphysics which it grounds, are fallibilistic and open to alternative