The following is a preview selection (rough draft) of the forthcoming Quaestiones de Quodlibet, Prima Series, based upon the questions I received this past July/August. This is the respondeo portion of q.1, “On Knowledge”, a.1, “How does intellectual knowledge differ from sense knowledge?”
I respond: We must distinguish the faculties and operations of sense perception and intellect.
The ancient philosophers of Greece posited many theories of knowledge: some that we know things outside of ourselves by a material likeness to those things (e.g., that we know a rock by having a tiny bit of rock in ourselves) or that all knowledge was purely sensory; others, that we receive an influx of atoms too small to be seen which inform our understanding (such was the theory of Democritus, a kind of atomistic reductionism echoed today); others still held that we are essentially immaterial beings and attain a freedom of the intellect from the body when we gain intellectual vision of immaterial forms (Plato); and finally, with Aristotle, a kind of culmination is reached: not in that he attained the whole truth, but in that the truth he attained being more accurate a grasp of the whole than any of his predecessors.
For Aristotle recognized three levels of cognitive operation: sensation, perception (or what he called, generally, imagination), and intellection. We will not dwell here on the controversies of interpreting Aristotle or the scholastics who followed him, but we will focus instead on laying out the truth which they grasped.
First , let us begin with defining some terms. Answering this question adequately requires some terminological complexity, and so it is important to be clear about how terms are being used. Cognitive operations refer to acts or series of related acts whereby some object is brought into awareness: in other words, that the object is established as what terminates a relation from some subject. Object here does not mean “a thing independent of my awareness” (a modern perversion of the term object), but rather, “that which is precisely as regards some cognitive faculty”. Faculties (also called “powers”) are those properties belonging to a living being whereby it is capable of operation: as a human being has faculties of locomotion, sensation, volition, etc. Cognitive faculties are distinguished primordially by recognition of their respective distinct objects: that is, to give a simple example, we know that sight and hearing differ from one another in that the former has light for its object (on the spectrum of ~380-740nm), while the latter has vibrations of a certain frequency for its object (~20-20,000hz), each of which kind of object requires a distinct organ in order to be sensed. To give a more complex example, we recognize that some objects of our awareness are present before us here and now, and thus enter into our awareness both on account of our faculties and on account of their appearance, while others are in our awareness before us solely through an operation on our own part.
This distinction posits a basic separation between what John Poinsot (among a larger tradition) termed intuitive awareness and abstractive awareness, or the awareness of a present thing and the awareness of an absent thing. Within abstractive awareness, there are different ways in which an object may be in such awareness: as of a thing encountered past, or of a thing creatively imagined, or of a thing understood precissively considered apart from any of its particular instances (though still imagined in some way). For instance, I may be abstractively aware of the house in which I grew up, which is not present to me, but is recalled as an object of the past; or I may be abstractively aware of Gilbert Dasein, a fictional character in Frank Herbert’s science fiction story, The Santaroga Barrier—or of a unicorn, both fictional objects never present to me as such, but creatively imagined; or I may be abstractively aware of canine nature (no dogs being present with me in the room at this time), something which I never experience strictly in itself but always in some limited instantiation.
Crucially, we must point out that every object presupposes a sign. A sign is a triadic relation (i.e., always and irreducibly connecting three distinct terms), whereby the object determines a sign-vehicle which in turn determines an interpretant so that the interpretant is disposed in a certain way towards the object. All cognitive faculties are interpretants, and therefore attain their objects through the mediation of sign-vehicles.
Second , a distinction too often missed must be made between sensation and perception. That is, sensation is a purely passive reception of objects; the sense faculties are put into operation by light, vibrations, etc., acting upon the sense organs. In other words, a specifying form is impressed upon the organs, such that the form is received according to the mode of the receiver. For instance, non-human animals receive light specifications in differing wavelengths than our own, as mosquitoes, piranha, and butterflies. These impressed specifying forms (species impressae sensatae) in our experience are not to be confused, however, with the impressed specifying forms of perception: which are not of sensible qualities, but of objects as carried by sensible qualities. To illustrate the distinction by means of an example, consider your current surroundings: there are many things which you presently are sensing of which you are not perceptually aware until your attention is brought explicitly to those things (making them perceptual objects). For instance, there are likely clothes touching your body, a chair in which you are sitting, noises in the background, things seen in the corners of your eyes, even perhaps a flavor on your tongue or an odor in your nose. We do not sense clothes, chairs, the sound of an overhead airplane, but rather textures, resistance, and a loud but distant and low noise; yet we do perceive that the clothes are uncomfortable, or that the chair is too-high for …, or that the airplane’s noise indicates that it is low, and so on.
To understand more precisely the relation of sensation and perception, it is helpful to discriminate various faculties involved in the related operations in the order of knowledge’s genesis.
We begin with are the commonly-known exterior sense faculties of sight, hearing, smell, taste, and the generic sense of touch. Each of these has a distinct organ: eyes, ears, nose, tongue, and a multitude of nerves responsible for discerning the species of touched objects. It should not be thought that the organ and the faculty are, however, identical: that is, they refer to the same operation, but have different being, for the organ receives by a corporeal change and the faculty by the intentional change. Following the proper reception of sensible forms, there is the faculty which in Latin has often been called the sensus communis, but which I interpretively translate as the “integrating sense”. That is: we do not merely sense lights and sounds, but wholes. That is, we do not merely receive an impression of sense quanta, but through our proper exterior senses we receive also a certain sensory object, as a whole: In other words, by means of the corporeal change of the organ, there is received an intentional form of the object, the aforementioned species impressae sensatae. The organ of this reception is the brain, which is capable of cognizing through these sensations that there are distinct objectivities to which we may be cognitively related, and the integrating sense is the faculty responsible for the apprehension of this whole. which may then, by the interior sense faculties—which may also be called the perceptual faculties or the phantasiari—be formed into the perceptual species impressa or the species impressae phantasiari. We sense light, but we perceive objects. We cannot perceive without having sensed, but we may sense without having perceived, as shown in the fact that without altering our sensations we may alter our perceptions (as now I perceive the chair in which I am sitting, and now the desk in front of me, the first through my sense of touch and the second through my eyes).
The species impressae phantasiari are not, unlike the species impressae sensatae, simply received passively. Rather, as objects, we begin to think about them. This entails a multitude of operations requiring a plurality of faculties. Aquinas distinguished these faculties in human beings as the vires imaginativa, memorativa, and cogitativa (with the lattermost, in non-human beings, termed the vis aestimativa), which I interpretively translate, respectively, as the faculties of sensory retention, pattern retention, and cogitation. These faculties—which we share in common, albeit with various biologically-grounded differences, with other animals—have the brain for their organ. While some parts of the brain may ordinarily play a greater role in the operations of each faculty, a precise mapping has not been attained and may not be possible: due to the nature of the brain’s structure, it seems that the materiality of the brain entails the possibility of adaptive allocation of its resources.
The faculty of sensory retention has for its object the preservation of the experience of individual sensations: as even though no green color is present to my sensation at the moment, I retain a sensation of green objects. The faculty of pattern retention has for its object the totality of relations through which an experience occurred in some time past: as one recalls, for instance, a pleasant visit to St. Patrick’s Cathedral in New York City, in February of 2016, on 5th Avenue, across from which is a famed statue of Atlas holding up the world—a recollection entailing both intellectual contributions (such as that there exists a thing called St. Patrick’s) as well as the various immuted incidental perceptibles; or, for a much simpler example held in common by all animals, of a safe location where one sleeps at night. The faculty of cogitation or estimation has for its object the evaluation of the object’s potential benefit, harm, or neutrality with respect to the animal evaluating it. It is through such evaluative consideration that an object as perceptual comes to the fore; though this unity between perceptual evaluation and objectivization is, for us as human beings, whose intellectual faculty (which we will discuss momentarily) heavily influences our cogitative faculty, difficult to recognize as such.
Through the operations of these perceptual faculties, the species impressae phantasiari are rendered into species expressae, expressed species, through which the animal is re-oriented towards its objects. For instance, a sheep is passive in its sensory apprehension, but through the integrating sense and perceptual faculties, forms a species impressa of a wolf and by its vis aestimativa, it produces a species expressa phantasiari by which the perceived wolf is judged harmful, and the action of fleeing is accordingly taken.
By the faculties of sensation and perception, every animal lives in a relationally-constituted world of objects. The objects of perception have their meaning for those animals determined through those relations; as a domesticated dog views its master not simply as a congeries of sensed qualities, but as good-for-itself, providing food and affection, and other such benefits. It may thus appropriate the master as part of its own referential context of good: such that harm to the master becomes perceived as harm to itself, and it acts accordingly.
Third , we must distinguish that a faculty belongs to human beings, the nature of which has been mistakenly conceived by the majority of philosophers for centuries and continuing into today. This is the faculty of the intellect. Many people—arguably most in recent years—have thought the human intellect no different in kind from those faculties commonly possessed by all animals, only more developed, complex, and sophisticated; differing, that is, only in degree. What has not been recognized by the philosophers and other thinkers making this mistake is that the human intellect has a radically different object for its operations: that is, where other animals are concerned only with the referentially-contextualized meaning of their objects (which is to say, what those objects mean as respecting the potential benefit or harm of the animal itself), humans are concerned by nature with the intelligible meaning of the objects themselves, as what they are in and of themselves. Neither dog, nor dolphin, nor chimpanzee will contemplate their own natures, nor the nature of one another, nor of the sun, nor of the earth, nor of water. They cannot escape referentially-contextualized meaning, for they do not have a faculty with being for its object.
That is: given the faculty of intellect, a human may see in perceptual objects, brought into our awareness by the species impressae et expressae phantasiari, more than a merely referential context of meaning: we may, from those species expressae, gain an insight into the being of the objects: and thereby form a species impressa intelligibilis. This, subsequently (through operations of composition and division, or, more broadly named, interpretation), is formed into a species expressa intelligibilis, by which the intellect is re-attuned to the object in a way comprehending not only its intelligible meaning, but also its referential meaning presented by the species expressa phantasiari.
To recapitulate: our awareness begins through the operations of sensation. Our senses receive specifications from sensible objects which are themselves in act in a way to which our sense organs are attuned; such that my eyes may perceive light of a certain intensity and wavelength, and the nerves in my hand can receive textures and temperatures by relative variations. All of these sensations are received into the brain where they may be processed by the integrating sense and therefore perceived as belonging to certain objective wholes, through the operations of the perceptual faculties. By these perceptual faculties, these objects are rendered meaningful in a referential context, i.e., how those objects stand in relation to myself as the one cognizing them. But as humans, when objects enter into our referential context, we are attuned to their being, and thus may and frequently do inquire into what those objects are themselves, as outside the practical context of referential meaning. The intellectual objects, then, include but go beyond what is given immediately and directly in sensation: for while sense allows for the relation between intellectual agent and object to be established, it does not give that relation as such.
 I have written on this at length elsewhere, as has John Deely, who has played a crucial role in reviving the Latin understanding of the term obiectum, an understanding we sorely need today. See Deely 2009: Purely Objective Reality, 8-15; Kemple 2019: The Intersection of Semiotics and Phenomenology, 15-16; Kemple 2019: Introduction to Philosophical Principles, 36-37, 52-54, and Gloss VI, 111-13. One may also consult my “15 Minute Insight” video, On the Meaning of “Objective”.
 Cf. John Poinsot 1632: Tractatus de Signis (TDS), III, q.1, 287/1-8: “Suppoenenda est definitione notitiae intuitivae et abstractivae, quam tradidimus lib. 1. Summul. cap. 3., quod notita intuitive est ‘notitia rei praesentis’, notitia vero abstractiva est ‘notitia rei absentis’. Ubi praesentia et absentia non sumuntur intentionaliter pro ipsa praesentia seu unione obiecti cum potentia.”
 To not here belabor the discussion: we may “absolutely consider” some intellectual object (an intelligible meaning, that is) but must always use some “phantasm” for attaining an actual understanding thereof (Aquinas 1266-68: ST Ia, q.84, a.7); which is to say that there is a difference between imagining a thing as a whole—as if I am imagining a cup of coffee as a nice afternoon pick-me-up—and imagining a thing wherein that imagination is subordinated to an operation of absolute consideration—as if I am imagining a cup of coffee in order to contemplate the nature of coffee itself.
 Deely 2010: Semiotic Animal, 93: “The element in the foreground of representation is the sign-vehicle, what is loosely and commonly called a ‘sign’, and which can be pointed to or seen or heard when it occurs outside the psychology (the subjective states) of the organism. The element itself represented (the ‘self-representation’ in contrast with the ‘other-representation’ of the ‘representamen’ or sign-vehicle) is the object signified or significate, which is represented in or by the sign-vehicle; and the one to or for which the representation of sign to signified is accomplished Peirce called ‘the Interpretant’, in order to make the point that it need not be a person or even mental, which point, as I have had reluctantly to say already, is out of bounds for the present discussion.
“In this way it can be seen that objects, normally confused with things by human animals, are not only distinct in principle from (while yet always partially involving) things; but that objects also (what is far from evident, and indeed quite surprising) actually presuppose signs in order to be objects in the first place.”
 Though a topic too complex to enter into here, given this distinction we may recognize that plants may have a kind of sensory capacity, although not a perceptive one. Much has been considered in this regard within the field of biosemiotics and specifically phytosemiotics, the study of plant semiosis.
 Aristotle identified these (c.330bc: Περὶ Ψυχῆς, lib.2, c.6) as “incidental perceptibles” or “incidental sensibles”; that is, the objects are incidental to the sensations: 418a 21-25: “A thing is said to be incidentally perceptible, for example, if the white thing is the son of Diares, for this latter is perceived incidentally, because it is incidental to the white, that is perceived, for which reason nothing is acted upon by the incidentally perceived thing as such.”
 This is hinted at by Aristotle where he writes, c.330bc: Περὶ Ψυχῆς, 2.12, 424a 23-28: “The sense organ is the first thing that has the potency to be acted upon in that way [viz., through a proportionate ratio of the sensible object], so the organ and the potency refer to the same thing [operation and object], but the being of them is different; for the thing that does the sensing must be something extended, while its being a sense, or the being-perceptive of it, is certainly not of any size, but is a relatedness and potency of the part that has size.”
 Cf. Kemple 2019: Introduction to Philosophical Principles, 76-77; 156-158.
 The term phantasiari seems to originate (and until the recovery of John Deely, terminate) with John Poinsot, as a generic term to refer to all the perceptual faculties to be distinguished momentarily.
 1266-68: ST Ia, q.78, a.4.
 1266-68: ST Ia, q.78, a.4, c.: “Sic ergo ad receptionem formarum sensibilium ordinatur sensus proprius et communis, de quorum distinctione post dicetur. Ad harum autem formarum retentionem aut conservationem ordinatur phantasia, sive imaginatio, quae idem sunt, est enim phantasia sive imaginatio quasi thesaurus quidam formarum per sensum acceptarum.” – “Therefore, to the reception of sensible forms the proper and common [integrating] senses are ordained [together], of which distinction we will speak later [ad.1 and ad.2]. To the retention or conservation of these forms is ordained the phantasy, or imagination, which are the same, for the phantasy or imagination is as a certain repository of forms accepted through the senses.”
 This is an elaboration on 1266-68: ST Ia, q.78, a.4, c.: “Ad apprehendendum autem intentiones quae per sensum non accipiuntur, ordinatur vis aestimativa. Ad conservandum autem eas, vis memorativa, quae est thesaurus quidam huiusmodi intentionum. Cuius signum est, quod principium memorandi fit in animalibus ex aliqua huiusmodi intentione, puta quod est nocivum vel conveniens. Et ipsa ratio praeteriti, quam attendit memoria, inter huiusmodi intentiones computatur.” – “To apprehending those intentions which are not received by the [exterior] senses is ordained the estimative faculty; and to conserving those intentions, the faculty of pattern retention [vis memorativa], which is a certain repository of intentions of this kind. A sign of this faculty is that principle of recollection produced in animals from some such intention, such that [the object of the intention] is injurious or fitting. And the rationale of pastness, to which memory attends, is reckoned among these intentions.”
 This is the fundamental insight of the 19th century theoretical biologist Jakob von Uexküll, who denominated this relationally-constituted world of objects the “Umwelt” (um- a German preposition signifying “around” and Welt the German noun for “world”). Martin Heidegger (1929-30: Die Grundbegriff der Metaphysik) appropriates the idea in distinguishing between the “poor-in-world” non-human animals and the “world-building” human beings. The semiotics community, especially through the work of Thomas Sebeok, likewise appropriated the notion. For more, examine the index entries for Innenwelt, Lebenswelt, and Umwelt in Deely 2001: Four Ages of Understanding, 912, 922-23, 1008-09; 2002: What Distinguishes Human Understanding, 172 (Innenwelt and Lebenswelt), 178; and 2007: Intentionality and Semiotics, 234 (Innenwelt and Lebenswelt), 240, as well as Umwelt in Kemple 2017: Ens Primum Cognitum, 376 and the entries for Bildendwelt, Innenwelt, Lebenswelt, and Umwelt in Kemple 2019: The Intersection of Semiotics and Phenomenology, 333, 335 (Innenwelt and Lebenswelt), and 338.
 Aquinas 1266-68: ST Ia, q.5, a.2, c.: “Unde ens est proprium obiectum intellectus, et sic est primum intelligibile, sicut sonus est primum audibile.” – “Thus being is the proper object of the intellect, and is thus the first intelligible, just as sound is the first audible.”
 Cf. Aquinas 1259/65: SCG II, c.98, n.9: “propium obiectum intellectus ens intelligibile: quid quidem comprehendent omnes differentias et species entis possibiles; quicquid enim esse potest, intelligi potest.” – “The proper object of the intellect is intelligible being: which comprehends all differences and species of possible being; for whatever is able to be, is able to be understood.” Ibid, n.10: “Ex hoc autem quod substantia aliqua est intellectualis, comprehensive est totius entis. Unde, cum substantia separatae per suam naturam non fiat actu comprehendens totum ens, ipsa, in sua substantia considerate, est quasi potentia ad similitudines intelligibiles quibus totum esn cognoscitur, et illae similitudines erunt actus eius inquantum est intellectualis.” – “From the fact that some substance is intellectual, Much more so is this true of composite substances.
 In a way, this expands our own contexts of referential meaning, for we are, by nature, concerned with (or capable of concern for) the intelligible meanings of things. In this way, the good of beings other than ourselves can become our good, as in true friendship.