When my love swears that she is made of truth
I do believe her, though I know she lies,
That she might think me some untutor’d youth,
Unlearned in the world’s false subtleties.
—William Shakespeare, Sonnet 138
Within the annals of historical obscurity, Jean Roscelin has been writ larger than many other thinkers. This relative notoriety impresses all the more, since not a single extant writing by him is known. The reason his name still echoes has not only been remembered, but unconsciously assumed by many as a given truth; specifically, the concept of nominalism, originally conceived as the universal in speech having no referent in reality, but expanding —by virtue of its deeper root— to comprise all denials of relations in reality outside the mind or, what is effectively the same, their intelligibility. Nominalism is at the heart of the philosophies of not just Peter Abelard, John of Salisbury and William of Ockham, but of Descartes, Locke, Hobbes, Hume, Kant, and all the moderns (even, yes, the naïve realists), up through and continuing into today. It lingers in every manner of subjectivism or relativism, undermining the legitimacy of philosophy departments the world over.  It is only in the last hundred or so years that a genuine philosophical spirit has begun to break away from the its asphyxiating stranglehold with the upswing of realism (through phenomenology and from scholastic revivals), and through Peircean semiotics.
But these ragged breaths of philosophical renewal struggle to absorb clean air in an atmosphere densely polluted with the residues of nominalist presupposition. For one (and though this will not be our focus today, we will touch upon it), most of the industry which now claims the name of philosophy  unwittingly continues to eruct toxic, if green, naïve dualist assumptions that pitch self against world, mind versus body, nature as opposing culture. For another (and this is our focus), the atmosphere from which many living outside the “philosophical” industry and within what-once-was-the-West draw their beliefs remains nominalist throughout; with none having inhaled it quite so deeply as those who believe in the supreme fecundity of science above all things. The time has come to clear the air.
In their own practice, most natural scientists are realists, that is, engaged in the systematic application of empirical observation, experimentation, recording, and inference that constitutes the heft of their endeavours. But once outside the necessarily and deliberately narrow confines of inquiry into specific fields of study, a kind of naïve anti-realism pervades science.
Though personally unfortunate for the scientist, this naiveté is dangerous to others on a public level; for all too often, the scientist, puffed up by the near-religious fervor of a certain hoi polloi, comes to believe in the validity of his expertise outside the confines of his discipline. Sophistic pretence at philosophic wisdom furthers the problem, turning the practitioner into a prelate. It is bad enough to have Richard Dawkins dismissing ontological arguments with a sleight of his hand. It is worse to have Sam Harris reducing morality and the person to neurochemistry; and far worse to have Daniel Dennett and Patricia Churchland ejecting consciousness as epiphenomenal.
To be a scientist today requires specialised training in the application of specific ideas, techniques, methods and technologies at the core of which is the scientific method itself. To capture this specialisation, Jeremy Bentham —and after him, Charles Sanders Peirce— termed this branch of inquiry idioscopic science.  Its counterpart, the philosophical study open to anyone so long as they possess a sufficiently developed faculty of common reason, received the name of cenoscopic science. Along with mathematics as a third and separate class, Peirce considered these to exhaust what he called the “sciences of discovery” (joined by the “sciences of review” and the “practical sciences” in exhaustively dividing the whole of science). 
Because inquiry in cenoscopic science needs no specialised training, it is often assumed that its practice requires minimal to no training at all. Indeed, one could assume that very little is required for it beyond the ability to read, perhaps, in a few languages, and a course or two in logic. But even if, in a certain respect, this is so; the fact of the matter is that, for the purposes of cenoscopic science, time and study alone are not enough.
Idioscopic training is specialised because idioscopic practice is specialised. If one is going to study neurochemistry, one needs to know quite a bit of biology and chemistry, an awful lot of brain anatomy, how to conduct an fMRI, how to read the results of an fMRI, and so on. A neurochemist does not need to know Latin or Greek, when Aquinas wrote his commentary on Aristotle’s Περὶ Ψυχῆς, in which semester Heidegger taught his Prolegomena zur Geschichte des Zeitbegriffs, or whether Leibniz’s monadology had anything to do with Marx’s and Engels’ beliefs about the economic determination of social structure.
Neither does the cenoscopic expert, for that matter, need to know these things; but whereas these unnecessary-though-important questions have no relevance at all for the neurochemist in functioning as a such, they are profoundly relevant to the philosopher –even if he never asks them. The philosopher is, for that matter, also concerned with biology and chemistry, fMRI results, norepinephrine, serotonin, dopamine and all the rest that could concern the neurochemist; as well as with Dante’s terza rima; whether Caravaggio’s themes of sin and desperation for redemptive action speak to something perennial in the human experience; if Wittgenstein or Chomsky better understood the role and function of words; and whether non-human animals exhibit true language —to name just a tiny fraction of the things that can and perhaps ought to concern every philosopher. 
Common reason —the only instrument of cenoscopic inquiry— has for its material object everything; which is not to say that idioscopic practice stands subordinate to the heteronomous dictates of cenoscopy. To the contrary, cenoscopy must hold the discoveries of idioscopy in the highest regard, for —given the current state of the collection of human knowledge— idioscopy principally discovers new phenomena, since there are few particulars as yet to be discovered by common reason (albeit always greater depths to be plumbed in the old phenomena).  Through specialised training and instrumentation, we can unveil aspects of the real that we were unable to discern by virtue of our natural powers of observation. Democritus may have hypothesised the atomic structure of the universe —and even that light moves—, but it took in excess of 2200 years to prove that he was not so far off the truth as Aristotle argued. Technological and mathematical advances in the Renaissance and the Enlightenment gave ever more precise portrayals of the extraterrestrial cosmos; while improved navigation, medical practices and instruments, cataloguing and the development of chemistry revealed more of the world on which we live.
That said, there is no specialised training or instrumentation (including the most sophisticated so-called “artificial intelligence”) that can detect meaning:  the formal object of cenoscopic inquiry. Though no more a historian than he is a biologist, the philosopher discovers in the works of every realm of inquiry the intelligible parts which speak to a whole that’s circumscribed by neither. To recast the mereology in more grandiose terms, idioscopy discovers truths which stand as parts to the whole of truth that cenoscopy seeks.
Believing that this heavy task takes no more training than persistence in thinking and reading presumes that thinking is a self-correcting activity;  though the past centuries have proven it to be anything but.
These two modes of observation, the idioscopic and the cenoscopic, ought to complement each other, since they have the same ultimate object —truth, in general— but different means of reaching it. As I have argued elsewhere, cenoscopy must be phenomenological because it gets at meaning by destroying complacency (in the adequacy of our understanding) and therefore allowing beings to be. Idioscopy, on the other hand, delimits a tapered realm in which a being may or may not be. By the methods of falsification (per Popper, or “fallibilism”, per Peirce), one can only ever disconfirm a causal relation between the delimitation of one’s study and the appearance of a being. In other words: idioscopy attempts to eliminate false explanations one at a time and, from the sum of that activity, to indicate (but never to confirm) its particular truths; this being, notably, its practice now, if only recently. For much of idioscopy’s distinct history —i.e., since the “scientific revolution,” when idioscopy became distinguished from cenoscopy by having not only a distinct methodology but also a more-specified object— it has instead practised a sort of verificationism, a belief which yet lurks behind many ostensibly “falsificationist” practitioners who claim only to disconfirm as they simultaneously imply the indisputability of some positive claim.
Regardless of whether an idioscopic scientist seeks verification or falsification, the pollutant that our intellectual atmosphere spews forth comes from the combination of delimited investigation (idioscopic method) with the failure to develop well-trained limitless receptive consideration (cenoscopic inquiry). To illustrate this: C.S. Peirce, speaking before an eclectic group gathered at Harvard in the spring of 1903, took to describing the sameness of sensory objects across not only individual humans, but through species: 
“[My dog] does not think of smells as sources of pleasure and disgust but as sources of information, just as I do not think of blue as a nauseating color, nor of red as a maddening one. I know very well that my dog’s musical feelings are quite similar to mine though they agitate him more than they do me. He has the same emotions of affection as I, though they are far more moving in his case. You would never persuade me that my horse and I do not sympathize, or that the canary bird that takes such delight in joking with me does not feel with me and I with him; and this instinctive confidence of mine that it is so, is to my mind evidence that it really is so. My metaphysical friend who asks whether we can ever enter into one another’s feelings —and one particular sceptic whom I have in mind is a most exceptionally sympathetic person, whose doubts are born of her intense interest in her friends— might just as well ask me whether I am sure that red looked to me yesterday as it does today and that memory is not playing me false. I know experimentally that sensations do vary slightly even from hour to hour; but in the main the evidence is ample that they are common to all beings whose senses are sufficiently developed.
I hear you say: ‘All that is not fact; it is poetry.’ Nonsense! Bad poetry is false, I grant; but nothing is truer than true poetry. And let me tell the scientific men that the artists are much finer and more accurate observers than they are, except of the special minutiae that the scientific man is looking for.”
The hundred and fifteen years since Peirce delivered these words have seen considerable improvement in the idioscopic understanding of animal perception; we know, as he did not, that the bull does not see red. We know that a dog’s sense of smell can distinguish every ingredient of a stew, whereas we can typically detect only the combined product, and that canine hearing extends to sounds roughly 22,000 Hz higher in pitch than our own. But nowhere in the discoveries of ocular cone receptors or the complexity of olfactory structure, of degrees of pitch or oscillations in photon wavelengths, nor in any other discovery made through the methods of idioscopy, does one detect sympathy, pleasure, disgust (outsize claims of dopamine correspondence notwithstanding a moment of intelligent reflection, nor any other chemical), or sameness. At best, one finds correlates which appear always or perhaps only for the most part; perhaps even as necessary consequences or antecedents. But the greatest accretion of idioscopically discovered correlates, whether antecedent, consequent, or contemporaneous —and be these hormones, chemicals, facial tics, neural patterns, etc. —will never yet amount to an iota of meaning.
Rather, while one may stumble upon meaning through any use of common reasoning, to illumine the truth of those discoveries one needs the research of cenoscopy. Unfortunately, the absence of good training in the practice of common reasoning has for centuries resulted in an excess of “bad poetry” (by which I do not mean Maya Angelou’s “Old Folks Laugh,” though it undoubtedly counts). Good poetry –or true poetry, as Peirce has it— is what Heidegger calls “the original language,”  the bringing to presence das Sein des Seienden, disclosing a reality which might otherwise be covered up by our routine, reductionist, myopic, cloudy, eliminative and ordinary habits of observation.
The nominalist presuppositions infecting philosophy have achieved the opposite, for one of the results of nominalist inspiration (or inhalation) is the severance of meaning —which, if it is to be anything, is necessarily to be something relational— from the things of the world.  Instead, all meaning becomes circumscribed within the sphere of an individual’s frame of referentiality. Meaning is then understood to have no basis in the intelligibility of the object, but rather has its meaning determined solely by reference to or for some mind;  which is to say, meaning becomes truncated by implicit nominalism. Idioscopy discovers new facts —and the cenoscopically miseducated mind makes, rather than discovers, their meaning.
This would play poorly if its one result was merely the post-hoc cenoscopic misinterpretation of idioscopic discovery. But the practice and structure of idioscopy are related to cenoscopy not only by the former providing the latter with new facts from which to draw meaning; idioscopy is, prior to any of its discoveries, entirely dependent upon “the virtual assumption of sundry logical and metaphysical beliefs”.  The fault of ill-conducted or ill-principled cenoscopy is thus not only failing to provide idioscopic practitioners with sound presuppositions, but frequently supplying them with outright wrong or stupid ones.
The results of this are proving to be nothing short of cataclysmic. For one, the idioscopic practitioner must take certain terms and concepts for granted, and as such they must be pursued through cenoscopic inquiry. One such concept often found in idioscopic practice is that of “nature” and the “natural”: terms which, despite the widespread rejection of the existence of natures (except as tentatively and perhaps reluctantly held in opposition to the artificial), carry a normative weight. To label a behaviour as “natural” is to sanction it (likewise, to a lesser degree, “ordinary”, “normal”, “typical”, and any other categorisation which suggests that some action belongs to the regularly-scheduled operations of being human). When one believes that the “natural” comprises no more than what occurs independently of human action, however, the “natural” loses the heart of its meaning; for in this sense, the “natural” is actually quite aberrant. We should all gag over such a confusion. Yet ubiquitously —and it is little surprise— we see the aberrant declared as normal by idioscopic practitioners, especially psychologists and social scientists.
Conversely, we find a mechanistic and reductionistic obtuseness holding sway among practitioners of idioscopic sciences that deal with more determinate behaviour —like atomic forces and chemical combinations—, for whom “natural” signifies strict and lawful adherence to invariable principles. So whereas the psychologist might call “natural” behaviours which are wildly aberrant, the physicist will see little of nature in any variegated domain of action, except insofar as they can be reduced to the regular actions of molecules, atoms, and particles.
Idioscopy also relies ubiquitously on logic —logic not only in the sense of valid syllogistic forms, distributed middles, and De Morgan’s law, but also in the sense of icons, indices and symbols, of Suadisigns and Dicisigns, of rules and types of inference, and all the study of the operations of thought— which is not simply a study of the mind, but a great deal more. A failure to understand the laws of thought is a failure to understand how one’s research can, must, or ought to proceed. All the recent years’ brouhaha over unconscious bias in scientific practice, for instance, stems almost certainly from an ignorance about how ideas take shape in the first place —and, for that matter, what ideas are.
And so with worse cenoscopic practice comes not only worse interpretation of idioscopic discovery, but also shakier foundations for the latter’s practice.
Then there are the true poets. Peirce claims them —and all true artists— to be “much finer and more accurate observers” than the scientists. Many scientists, no doubt, will balk at this (so too, I can imagine, will many who presume themselves philosophers). But both the scientists and the self-proclaimed philosophers misunderstand the nature of artistry, not in the sense of τέχνη, but in the sense of poetry as the flourishing of ποίησις, a bringing-forth of what-is through language. This understanding has been lost to the sophists in their attempts to make philosophy like science, or to “improve” cenoscopy with idioscopic methods. In truth, the philosophical endeavour is much closer to the poet’s, who, per Heidegger: 
“…is not he who writes verses about the respective present. Poetry is no soothing for enthused little girls, no charm for the aesthetes, who believe that art is for savoring and licking. True poetry is the language of that Sein that was forespoken to us a long time ago already and that we have never before caught up with. For this reason, the language of the poet is never of today, but is always in the manner of having been and futurally. The poet is never contemporary. Contemporary poets, to be sure, can get organized, but they remain nonetheless an absurdity. Poetry, and with it, proper language happens only where the ruling of Sein is brought into the superior untouchability of the original word.”
In other words, the true poet is not bound by time, by fashion, by ordinariness or trends; he is never “contemporary”, but “always in the manner of having been and futurally” —which, in some sense, is the departure from ordinary time and entry into timelessness; where what is, is allowed to be what-it-is, and can therefore be seen, perceived, and understood as what-it-is and not as what we wish for it to be, or what we are expecting it to be —not what fits any abstraction or ideal.
Peirce says much the same —only, instead of saying that the language of the poet is never of today, he says, paradoxically, the opposite: 
“The poetic mood approaches the state in which the present appears as it is present. Is poetry so abstract and colorless? The present is just what it is regardless of the absent, regardless of past and future. It is such as it is, utterly ignoring anything else… The present, being such as it is while utterly ignoring everything else, is positively such as it is.”
We struggle perennially as humans, but especially here and now —being contemporary, being “scientific”— to see things as they truly are and not as we are used to seeing them through lenses of delusion and control. Allowing the present to appear-as-present is not so easy as it sounds.
Harder still is to signify the present—the timeless unveiled Being—for the terms by which we signify are signs: first of concepts and then, through them, signs of the things themselves; though the concepts may not be the same for all people at all times. By the same word, one may signify a well-formed concept to someone who has one ill-formed. The poet, the artist generally, succeeds by breaking through the obstinate insistence we have in believing our ill-formed concepts adequate, by bringing us closer to the present, by bringing us into the poetic frame of the present as present.
As to the philosopher, he strives to signify not only this primal reality —in which all that the philosopher signifies must always be based, to which it must always be phenomenologically reduced — but the dyadic and triadic relations which unfold from within it as evolutionary structures of not only intelligible but articulable meaning. Where the poet brings us to the present, the philosopher must bring the present’s intelligibility out of the hinc et nunc world of sense and feeling —indeed, out of time altogether. Where the nominalists, whether they be explicit adherents as vocal as Ockham or implicit adopters more subtle than Locke, create narratives ex nihilo to explain the scientific facts, the philosopher must discover that meaning as what really governs the present —both the fact and the experience of it— and, in so doing, make that meaning something that may be communicated across and beyond every barrier of idiosyncratic subjectivity.
 Cf. John Deely 2010: Medieval Philosophy Redefined, 130-36, 323-32; 2001: Four Ages of Understanding, 544f, 625f.
 As I have often stated elsewhere, most of what today goes by the name “philosophy” is in fact sophistry of such sophistication even the sophists genuinely believe themselves to be philosophers.
 Deely suggested altering the spelling to “ideoscopy” to indicate “within the scope of an idea” and avoid the association with the word “idiot”. I have waffled in my own commitment: for the Greek root of idio– suggests the particularity of the scope with, I think, more precision than is found in eidos/idea.
 Peirce, c.1902: “A Detailed Classification of the Sciences” in Collected Papers (CP) 1.241–42.
 The lack of such continuism –or “synechism”, as Peirce called it— being one of the grave faults in the contemporary philosophical industry which, in the absence of good philosophical training, has become overspecialised in envy of idioscopy; not unlike parents trying to ape the lingo of their children so that their children will like them.
 Peirce 1903a: “An Outline Classification of the Sciences” in The Essential Peirce (EP), vol.2, 259: “Philosophy is positive science, in the sense of discovering what really is true; but it limits itself to so much of truth as can be inferred from common experience. Idioscopy embraces all the special sciences, which are principally occupied with the accumulation of new facts.” Cf. 1905: “Review of Wilhelm Wundt’s Principles of Physiological Psychology”, CP.8.199
 Importantly, “meaning” can be said —as Aristotle said of “being”— in many ways. I believe there are three primary or ordinary ways in which we use it: 1) in designating the intelligibility of some object, as the answer to the question “what”, as when asked, “What do you mean?” or “What is the meaning of ‘human’?”; 2) in identifying the reference of a sign, as “What do you mean by ‘that’?” or “’Bark’ meaning that of a tree or a dog or a ship?”; 3) as portraying the importance of the object and thus its magnitude for one’s life, as “What is the most meaningful thing in life for you?” or “Why is that picture meaningful to you?” Respectively, I call these the “intelligibility”, “referential”, and “teleological” senses of meaning (the first two corresponding to Heidegger’s use of Sinn and Bedeutung).
 An optimism to which Peirce held, but to which I do not; indeed, had Peirce been warier of human smallness, he may not have had his career so persistently undermined.
 1903b: “The Seven Systems of Metaphysics” EP.2, 193.
 1934: Logik als die Frage nach dem Wesen der Sprache, 170/145-46.
 See n.7 above.
 It is important to note that the meaning of some objects is determined at least in part by reference to a mind. That someone is female is independent of cognitive reference, that someone is a woman —as we tend to think of the term today— requires some referentiality beyond what is provided through nature, and that someone is a wife requires even more. That Ivan Karamazov authored the story of the Grand Inquisitor is entirely a referential-construct, since neither exists without some mind for whom it can be an object.
However, even in such instances of pure objectivity, the intelligibility is primary over the referentiality, for the intelligibility exists as potency prior to being realised in actuality. Just as a dead or alien language that no one could understand at present may be understood in the future; so too, for a fiction to be understood, it needs to be composed from elements themselves intelligible. Consider the effect that a plot hole or an inconsistency has on a work of storytelling: it ruins not just a moment, but the whole story’s coherence; it breaks said fiction’s world.
 Peirce c.1905: “Consequences of Critical Common-Sensism” in CP.5.521.
 Heidegger 1934: Logik als die Frage nach dem Wesen der Sprache, 170/146.
 Peirce 1903c: “On Phenomenology” in EP.2.149-50.
 Which is a relational re-duction, a leading-back-into, and not an eliminative reduction (like a boiled-down sauce).
Deely, John. Four Ages of Understanding: The First Postmodern Survey of Philosophy from Ancient Times to the Turn of the 20th Century. Toronto: University of Toronto Press, 2001.
—–. Medieval Philosophy Redefined: The Development of Cenoscopic Science, ad354 to 1644 (From the Birth of Augustine to the Death of Poinsot). Chicago: Scranton University Press, 2002.
Heidegger, Martin. Logik als die Frage nach dem Wesen der Sprache (Frankfurt am Main: Vittorio Klostermann, 1998), and in the English translation by Wanda Torres Gregory and Yvonne Unna (Albany, NY: SUNY Press, 2009), Logic as the Question Concerning the Essence of Language .
Peirce, Charles Sanders. “A Detailed Classification of the Sciences” in Collected Papers, vol.1 of 8, §203-283. Cambridge: Belknap Press of Harvard University Press, 1958-1966 .
—–. “An Outline Classification of the Sciences” in The Essential Peirce, vol.2 of 2, p.258-262. Bloomington: Indiana University Press, 1998 [1903a].
—–. “On Phenomenology” in The Essential Peirce, vol.2 of 2, p.145-159 [1903c].
—–. “The Seven Systems of Metaphysics” in The Essential Peirce, vol.2 of 2, p.179-195 [1903b].
—–. “Consequences of Critical Common-Sensism” in Collected Papers, vol.5 of 8, §502-537 [c. 1905].
—–. “Review of Wilhelm Wundt’s Principles of Physiological Psychology” in Collected Papers, vol.8 of 8, §196-204 .
Brian Kemple is the author of Ens Primum Cognitum in Thomas Aquinas and the Tradition and The Intersection of Semiotics and Phenomenology. He received his PhD in Philosophy with the Center for Thomistic Studies at the University of Saint Thomas, Houston TX, in 2016, and is the only student ever to complete a dissertation under the direction of John Deely. He currently consults as a Research Fellow with the Center for the Study of Digital Life (www.digitallife.center) and operates a private philosophical consulting and education service, Continuum Philosophical Insight (www.cp-insight.com).