1 Take a few moments, and imagine you are relaxing in a nice hot bath. You can feel the heat and pressure of the water on skin over the whole length of your body. From time to time you glide your hand through the water and feel the water flowing through your fingers in a distinctive (and pleasant) way. Your eyes are open, and you are gazing at the ceiling of your bathroom, watching the steam slowly swirling around the room. Your auditory sense is also active: you can hear the constant drone of traffic noise from outside, along with music from a neighbouring apartment (if your bath is very hot you will also be hearing the sound of blood pumping through your ears). And that’s not all: you are also enjoying a rich and varied “inner” stream of consciousness. You are currently thinking about what to have for dinner later on; a few moments before that you were feeling annoyed about the neighbours’ music, and wishing the noise would go away; and before that you had spent several minutes replaying memories from your holiday earlier this year. This all takes place against the backdrop of the gentle feeling of contentment resulting from your doing nothing but float in warm water.
2 As a description of the character of what your experience would (very likely) have been like in the envisaged circumstances this sketch is incomplete, in two very different ways. A more accurate and discerning phenomenological account of the brief period in question would no doubt be far more detailed than what I have provided above. Our day-to-day states of consciousness are massively varied and subtly detailed; anything resembling a full picture of even a couple of minutes experience of ordinary human consciousness – even assuming such a thing is possible – would no doubt fill several pages.  No less importantly, and more relevant to my present concerns, a phenomenological description which confined itself to merely listing the specific forms of experience which could be found in a typical stream of consciousness, and made no mention of the fact that these experiences are all unified, would be radically incomplete. In the case above, your bodily sensations (deriving from the hot water pressing in on your body) are experienced along with your visual experiences (of the ceiling), your auditory experiences (of the traffic and music) and your conscious thinking, your mental imagery, your emotional mood. As a first approximation, everything you are experiencing – your overall or total experience – is experienced as unified. That our ordinary episodes of consciousness at a given time are massively unified is such a ubiquitous and basic feature of our ordinary experience that it is easy to overlook – and many of us may even be quite oblivious to existence – but this distinctive form of phenomenal unity (as we can call it) is a fundamental feature of our consciousness.
3 For philosophers in the Cartesian tradition the unity of consciousness poses few if any problem. In Méditation 6 Descartes remarks: “When I consider the mind, or myself insofar as I am merely a thinking thing, I am unable to distinguish any parts within myself; I understand myself to be something quite single and complete.” For Descartes, all our experiences are modes or modifications of metaphysically simple (immaterial) substances. Since the essential nature of these substances is precisely to house unified states and streams of consciousness, the question “What explains phenomenal unity?” has a quick answer. Since modes cannot exist apart from their substances, to think your toothache could exist all by itself, in total isolation, makes no more sense than thinking a hole in a lump of cheese could exist independently of the lump. Moreover, by virtue of being simple (in the sense of lacking any true or separable parts), Descartes’ immaterial substances cannot divide into two (or more) in the manner of an amoeba, or merge in the manner of clouds, or pools of water. For Descartes, and those who follow in his footsteps, unity is a necessary and unbreakable feature of our consciousness.
4 Determined as he was to pursue a “psychology without a soul”, these quick and easy solutions to the problems posed by the unity of consciousness were not available to Brentano. While his discussion of the issue in Book II, Part IV of Psychology from an Empirical Standpoint is not without its problems and lacunae, it would not be the path-breaking accomplishment that it unquestionably is if Brentano had not held firm in rejecting the Cartesian framework. 
5 To make matters more concrete, let’s focus on an artificially simple example of a total experience. Figure 1 below represents a state of consciousness E at a given time t, comprising four experiences: a visual sensation e1, a bodily sensation e2, an auditory experience e3, and a mental image e4. For present purposes, we do not need to dwell on what the precise character of any of e1, e2, e3, e4, and we can overlook the fact that each may well have its own internal complexity, and hence possess experiential parts of their own. The double-headed arrows indicate that each of these experiences (or experiential parts) is experienced as unified with all of the others.
6 What account can we give of this richly integrated state of affairs? The core elements of Brentano’s answer are to be found in this passage:
Our investigations lead to the following conclusion: the totality of our mental life, as complex as it may be, always forms a real unity. This is the well-known fact of the unity of consciousness which is generally regarded as one of the most important tenets of psychology.
The unity of consciousness, as we know with evidence through inner perception, consists in the fact that all mental phenomena which occur within us simultaneously such as seeing and hearing, thinking, judging and reasoning, loving and hating, desiring and shunning, etc., no matter how different they may be, all belong to one unitary reality only if they are inwardly perceived as existing together. They constitute phenomenal parts of a mental phenomenon, the elements of which are neither distinct things nor parts of distinct things but belong to a real unity. This is the necessary condition for the unity of consciousness, and no further conditions are required (Brentano, 1874/1995, p. 126).
8 To provide anything approaching a complete picture of what Brentano is offering us here would mean engaging with some of the most distinctive (and inevitably) controversial aspects of his philosophy: the nature of “real unities” and “inner perception”, for example. I shall be touching on some aspects of these issues, albeit briefly, later on. For now I want to focus on just one important and distinctive element of his position. Returning to our total experience E, according to Brentano its constituents parts, e1, e2, e3 and e4 are phenomenally unified if and only if they are experienced by us as occurring together (or “inwardly perceived as existing together” as he puts it). Whereas Descartes appealed to co-instantiation within a substance to explain the unity of consciousness, Brentano appeals to a phenomenal relationship: contents or objects are unified in consciousness if they are experienced as existing together. Let us say (for obvious reasons) that experiences related in this way are co-conscious.
9 Brentano’s solution has a number of appealing features. From an ontological point of view it is economical: phenomenal unity is being explicated without reference to any underlying substance. From a metaphysical point of view it is highly flexible. It is possible to combine the claim that experiences at a given time are unified if they are co-conscious with a range of views concerning the nature of consciousness and its relationship with the physical world (those who believe experiences are immaterial can subscribe to Brentano’s view, but so too can those who believe they are identical with neural activity in our brains). The view is also plausible on a phenomenological level. Recalling your time in the bathtub, can there really be any doubt that you do experience your bodily sensations as existing along with your visual experiences, and hence as co-conscious with them?
10 From a purely phenomenological standpoint this form of unity seems to be both primitive (not explainable in terms of anything else) and unmediated. When two experiences, of whatever kind, are experienced as existing together the relationship between them is direct and immediate: we are not aware of any third ingredient linking two co-conscious experiences; yet the experiences in question are experienced together rather than separately. Brentano’s relationship is also a pervasive one: quite generally, all the parts of a typical state of consciousness at any one time are co-conscious with one another.
11 When Brentano claimed that the “totality of our mental life, as complex as it may be, always forms a real unity” he was referring to the totality of our conscious mental life, since he refused to countenance non-conscious forms of mentality. He also had something quite specific in mind in talking in terms of a “real unity”.
12 Brentano distinguished between different grades of entity. What he classed as genuine entities – such as elementary particles – possess real unity. These are contrasted with entities which do not possess real unity; these lesser things Brentano calls “collectives”. Of the latter he writes:
A city, indeed each house in a city, each room in the house, the floor of each room, which is composed of many boards, are also examples of collectives. Perhaps the boards themselves are collectives composed of many elements, whether points, or indivisible atoms. […] One thing, however, is certain: without some real unities there would be no multiplicities, without things there would be no collectives (ibid.).
14 As is clear, many paradigmatic material things (such as houses, and planks of wood) do not possess the kind of unity Brentano requires genuine things to possess: houses and planks are classed by him as mere collectives. It is also the case that since collectives are composed of (genuine) things, there would be no collectives at all unless at least some genuine things exist as well.
15 Collectives differ from genuine things (or unities) in a further way. A collective such as a house possesses many constituent parts, and many (if not all) of these parts can exist independently of the collective they happen to find themselves in. The bricks from which the walls of a house are constructed could – provided sufficient care is taken – be separated from the house, and used to build a different house, or a garden wall. The same applies to the atoms in a board of wood: these too can exist in different configurations (e.g. they could be re-assembled to form several books). Brentano holds that although genuine things – i.e., the possessors of real unities – often possess distinguishable parts or aspects, these are not capable of existing independently of the thing to which they actually belong. These dependent parts, or aspects, Brentano calls divisives. By way of an example, let us suppose elementary particles have a finite size: rather than being point-like, they are very small coloured spheres. Focusing on just one (red) particle of this sort, although its top and bottom halves cannot be separated – by virtue of being an elementary particle it entirely lacks separable constituents – we can easily discriminate these parts in thought. Parts of this kind are divisives, in Brentano’s sense (as is the colour of the particle).
16 Returning to the experiential case, in which class of entities do our total experiences at a given time fall? Are they collectives, or genuine things? On the face of it, there are significant differences between our total experiences and genuine things such as elementary particles. As usually conceived, the latter are extremely simple and changeless, whereas our total experiences are both highly complex and highly dynamic: the contents of our consciousness are continually changing, sometimes quite dramatically. Despite these divergences, Brentano holds that total experiences are in fact genuine things: co-consciousness (or experienced co-existence) is such a profound mode of connection that it renders total experiences more than mere collectives. As a consequence, the proper parts of our total experiences are divisives, and so incapable of existing independently of the experiential wholes they find themselves in at the time they exist.
17 If Brentano is right, total states of consciousness, despite their qualitative diversity and dynamism, are metaphysically akin to elementary particles. As Brentano himself concedes, this hypothesis “has its difficulties”, but he goes on to suggest that the difficulties confronting the hypothesis are less serious than they may initially appear: it is a mistake to suppose that complexity and real unity are incompatible. One difficulty he highlights derives from the fact that our sensory capacities are seemingly quite independent of one another:
If our simultaneous mental acts were never anything but divisives of one and the same unitary thing, how could they be independent of one another? Yet this is the case; they do not appear to be connected with one another, either when they come into being or when they cease to be. Either seeing or hearing can take place without the other one, and, if they do occur at the same time, the one can stop while the other continues. In this case of complexity, the mental acts are mutually independent (Brentano, 1874/1995, pp. 157-158).
19 An elementary particle that has a small number of intrinsic properties (e.g. a certain mass, a certain size and shape), and whose essential nature is such that it cannot survive even the slightest variation in these properties is one illustration of a real entity. But Brentano holds that it is possible for real entities – and real unities – to come in a range of different forms. An elementary particle might, for example, have two properties at t1, the power to repel F-type particles and G-type particles. At t2, this same particle could only possess the capacity to repel F-type particles, having lost its previous ability to repel G-type particles as well. Such variations in the (divisive-like) properties of a real thing are perfectly conceivable, argues Brentano :
That which is really identical cannot undergo any separation, since this would mean something being separated from itself. But that which belongs as a distinct part, along with others, may cease to be, while the other parts continue, without their being any contradiction (ibid., 163).
21 Consequently, there is nothing incoherent in the idea that at a given time a subject’s auditory and visual sensory capacities are both active and producing experience, whereas a few moments later only their auditory capacities are active (their visual capacities having just shut down as a consequence of the subject closing their eyes.) In such a case it is also true that a distinction needs to be drawn between (a) the total range of capacities for experience that a subject S possesses at a time t, (b) S’s capacities which are actually active at t, and (c) the total experiences these active capacities are jointly producing at t. It would be perfectly possible for someone to follow Brentano and hold that (i) all the proper parts of a total experience constitute a real unity by virtue of being related by co-consciousness, and also hold that (ii) the various capacities for experience that S possesses at t do not themselves constitute a real unity. After all, it is the parts of total experiences that are related by being experienced together, not the underlying capacities that are generating these experiences. 
22 The more one contemplates the unity of consciousness, the more remarkable it can seem to be. The pervasive manner in which every part of our typical total states of consciousness are experienced as existing together with all the other parts can seem a far deeper mode of integration than that which exists between the bricks in a wall (even when cemented together). Having no doubt spent a good deal of time pondering the unity of consciousness, Brentano was no doubt very familiar with its distinctive qualities. Consequently, his claim that the experiential parts of total experiences are divisives, incapable of independent existence, could conceivably be rooted solely in the intuition that we are dealing here with a very special form of unity. Some may be content to be led by intuition on this issue. However, for those suspicious of far-reaching metaphysical conclusions being based solely on intuition – whether Brentano’s or their own – what sort of argument can be brought to bear in defence of the phenomenal holism Brentano claimed to exist?
23 One line of argument appeals to “phenomenal interdependence” (as we can label it). At the moment, I am gazing at a computer screen, and enjoying total silence. My experience need not have been like this: it could easily have been the case that my visual experience of looking at the screen was accompanied by an auditory experience of (say) a drilling noise emanating from the building site next door, or the sound of a cello sonata emanating from my audio system. Now let us make some further suppositions: (i) that if my visual experience of the screen had been co-conscious with a drilling sound, its intrinsic qualitative character would have been different in a subtle but distinctive manner; (ii) if instead my visual experience had been co-conscious with a cello sound – but no drilling noise – its intrinsic features would also have been different, in a way which subtly but distinctively reflected the presence of the cello sound; (iii) that my auditory experience of the cello sound would itself have been different, in a subtle but distinctive way, if it had been co-conscious with a visual experience of looking at (say) a blue sky, rather than a computer screen; (iv) more generally, every part of every total experience is phenomenally interdependent, in this sort of way, with every other part.
24 To make matters more concrete, let us return again to the simple total experience E = e1, e2, e3, e4 depicted in Figure 1. For the sake of having some convenient shorthand, let us suppose that e1 is a V-type visual experience, e2 is a B-type bodily sensation, e3 is an A-type auditory experience, and e4 is an I-type inner experience. If the envisaged sort of phenomenal interdependence were to obtain, then a complete description of the phenomenal character of the constituents of E would have to mention all the other types of experience these constituents are co-conscious with, as shown below.
e1 at t: V-type + [B-type/A-type/I-type]
e2 at t: B-type + [V-type/A-type/I-type]
e3 at t: A-type + [V-type/B-type/I-type]
e4 at t: I-type + [V-type/B-type/A-type]
26 The first line provides a (rough) indication of the phenomenal character that e1 would possess if experiences were phenomenally interdependent in the way we are envisaging: e1 is not only a V-type visual experience, it is a V-type visual experience whose intrinsic phenomenal character has been impacted upon, in an utterly distinctive manner, by the fact that e1 is co-conscious with a B-type, an A-type and an I-type experiences. And similarly for e2-e4.
27 It is not difficult to see that phenomenal interdependence leads to existential interdependence. As standardly construed, token experiences are individuated by three factors: their subject, their time of occurrence, and their exact phenomenal character. If (as is here being assumed) subject and time of occurrence remain the same, the remaining factor to consider is phenomenal character. So let’s consider a counterfactual state of affairs, where at t the subject of E has a visual experience that’s qualitatively slightly different: it features a V*-type experience rather than a V-type. As can be seen, this change is reflected in full descriptions of the phenomenal characteristics of e2, e3 and e4.
e1 at t: V*-type + [B-type/A-type/I-type]
e2 at t: B-type + [V*-type/A-type/I-type]
e3 at t: A-type + [V*-type/B-type/I-type]
e4 at t: I-type + [V*-type/B-type/A-type]
29 Since an experience’s phenomenal character is essential to it, it is metaphysically incoherent to suppose a particular token experience can exist in a counterfactual scenario where it possesses a different phenomenal character from its actual character. Consequently, if phenomenal interdependence is a genuine property of experiential parts that are experienced as co-existing, then these experiential parts would be divisives, just as Brentano alleged. The phenomenal characteristics of the experiential parts e1, e2, e3 and e4 are such that they can only exist in total experiences which occur at t and consist of a V-type visual experience, a B-type bodily sensation, an A-type auditory experience and an I-type inner experience, all experienced together as co-conscious.
30 Phenomenal interdependence would provide Brentano with precisely what he needs. There are philosophers who have argued that this form of interdependence is a necessary and universal feature of consciousness. Timothy Sprigge, following in the footsteps of H. Bradley and W. James, is one such. Sprigge suggests that qualitative interpenetration, is introspectively discernible: “It is a commonplace of aesthetics and of right-minded psychology, but something we can each discover for ourselves, that every detail in the painting as a complete presentation has some difference, even within its own bounds, from what the detail would have if it were seen apart, or in another whole” (Sprigge, 1983, p. 219). Even if we are ordinarily inclined to assume that our total states of consciousness possess parts which could exist in states with a different overall character, in reality this is not the case:
Consider the character of a painting and the relation between its parts, when the painting is seen as a whole. …. [These] are in an important sense not real parts of the total experience, nor are any of its other components. This is because they lack an individual essence which could be specified or grasped without reference to the whole to which they belong. That is, an attempt to grasp what one of these components is, within the limits of its own being so to speak, could not [succeed] since its fully determinate form of being is something which involves its particular sort of contribution to the character of the whole (ibid., p. 170).
32 On a number of previous occasions I have expressed some skepticism with regard to this line of argument. While being fully convinced by the claim that the relevant form of interdependence is a real phenomenon – there are clearly cases in which the intrinsic character of an experiential part is affected by its phenomenal context – it does not follow from this that all parts of all experiential wholes are similarly interdependent .
33 However, as I have also argued elsewhere, so far as the case for experiential holism goes, the weakness of Sprigge’s case may not much matter. There is another, and perhaps more plausible, route to much the same place.
34 As we have already seen, the relationship of experienced co-existence is an intimate one. Experiences that are so related are apprehended as occurring together in a direct and unmediated manner – they are (in a manner of speaking) in immediate phenomenal contact with one another. Given this, it does not seem implausible to hold that when we come to spelling out the precise phenomenal character of any experience, facts concerning the relationships of co-consciousness which the experience in question enjoys cannot be ignored. If, for example, I am gazing at a painting, while also hearing the sound of drilling coming from a neighbouring room, then a full description of what it is like for me to look at the painting would be incomplete if it were confined to purely visual ingredients; a complete and maximally informative account of what it is like for me to look at the painting would refer to the auditory experience that is co-conscious with my visual experience. This will be the case even if the auditory experience is not a violent and disruptive aspect of my total experience, but a relatively minor and easily overlooked one.
35 If the experience is a total one, then the ways in which all its constituent parts are related to one another will feature in a full account of its phenomenal character. But equally, if the experience in question is only a proper part of a total experience, all the relationships of co-consciousness the part enjoys will also feature in a full description of its phenomenal character. Since in a total experience, irrespective of how we opt to decide it into parts, each and every part is co-conscious with every other part, then these two stories will be aligned.
36 In organizing the pertinent facts it will prove useful to distinguish two sorts of phenomenal properties. What we can call local phenomenal properties are the intrinsic features of an experience that we are accustomed to acknowledging. In the case of my visual experience of the computer screen I am currently looking at, this experience’s local phenomenal properties consist (roughly) of an expanse of colour extending through three spatial dimensions. An experience’s global phenomenal properties consist of those additional (relational) phenomenal properties the experience happens to have in virtue of being co-conscious with one or more other experiences. We may not be accustomed to recognizing that experiences possess these different types of property, but it is not implausible to hold that a phenomenological description which is maximally informative – one which registers all the phenomenal features and relations an experience possesses or enters into – will inevitably have to mention both sorts of property.
37 Extending this distinction to our simple total experience E delivers the following sort of picture.
e1 at t: L-character: V-type; G-character: [B-type/A-type/I-type]
e2 at t: L-character: B-type; G-character: [V-type/A-type/I-type]
e3 at t: L-character: A-type; G-character: [V-type/B-type/I-type]
e4 at t: L-character: I-type; G-character: [V-type/B-type/A-type]
39 Here “local phenomenal character” is abbreviated down to L-character, and “global phenomenal character” is shortened to G-character. The top line tells us that e1 has a V-type local character; the specified global character reflects the fact that it e1 is co-conscious with a B-type experience, an A-type experience and an I-type experience. The character specifications for e2-e4 work in a similar manner.
40 If the phenomenal characteristics of all experiential parts reflects the phenomenal characteristics of the entirety of the experiential wholes in which they find themselves, a form of phenomenal holism obviously obtains. Focusing again on e1, it is perfectly possible for an experience with the same local character (V-type) to exist in total experiences whose overall character is different. In the case below, for example, e1* is a V-type experience, one that is experienced with B-type and I-type experiences (as is the case with E), but an A*-type auditory experience (unlike the A-type found in E).
e1* at t: L-character: V-type; G-character: [B-type/A*-type/I-type]
e2 at t: L-character: B-type; G-character: [V-type/A*-type/I-type]
e3 at t: L-character: A*-type; G-character: [V-type/B-type/I-type]
e4 at t: L-character: I-type; G-character: [V-type/B-type/A*-type]
42 As can be seen, although e1 and e1* have the same local phenomenal characters in E and E*, their global characteristics are different, reflecting the differences in the kind of auditory experience which also exists in the relevant total experiences. As soon as we acknowledge the reality of both local and global characters, the assumption that token experiences can exist independently of their actual wholes collapses into incoherence, and Brentano’s claim that such tokens are mere divisives turns out to be true .
43 Would Brentano have availed himself of the distinction between local and global phenomenal characteristics if he had been aware of it? We cannot know. But, grounded as the distinction is in the relationship of experienced co-existence, the very relation Brentano set at the heart of his own account of the unity of consciousness, it is at the very least possible. In any event, when it comes to grounding phenomenal holism, there is another route that is available to Brentano and Brentanians.
44 In the passage from Psychology from an Empirical Standpoint cited earlier, Brentano writes: “The unity of consciousness, as we know with evidence through inner perception, consists in the fact that all mental phenomena […] belong to one unitary reality only if they are inwardly perceived as existing together.” In referring us to phenomena being inwardly perceived Brentano is drawing our attention to his doctrine that mental items are conscious if and only if they are accompanied by an “inner perception” or “inner consciousness” that they are occurring. According to Brentano, it is never the case that I just hear a sound; whenever I hear a sound I also have an immediate inner knowledge that I am hearing a sound – and similarly for all first-order forms of experience. Clearly, if Brentano’s inner perception doctrine is true, then when a subject has a collection of experiences that are experienced together as a unity, the subject will have an inner perception of this unity, just as Brentano suggests. That this fact may have holistic implications was not lost on Brentano:
inner experience seems to prove undeniably that the presentation of the sound is connected with the presentation of the presentation of the sound in such a peculiarly intimate way that its being contributes inwardly to the being of the other. This suggests that there is a peculiar interweaving of the object of the inner presentation and the presentation itself, and that both belong to one and the same act (Brentano, 1874/1995, p. 127). 
46 Although Brentano says little more by way of elaboration by what he means by claiming that the experience of a sound, and the inner perception of that sound “contribute inwardly” to each other’s being, it is not difficult to make some reasonable guesses. The “being” of a particular experience will consist, in part at least, in its experiential or phenomenal character. If inner perceptions and their presentations contribute inwardly to each other’s being, he may well have meant that these two inseparable aspects of consciousness are related in such a close and intimate manner that they are phenomenally interdependent: the phenomenal character of each is influenced the phenomenal character of the other.
47 Let us make these interpretive assumptions, and take another look at our simple total conscious state E. For present purposes we can leave the distinction between local and global character behind, and focus just on the local characters of the relevant experiences. A full description of the phenomenal character of each of E’s four constituents will now make reference to the accompanying inner perception, which will in turn make reference to each of the constituents that are experienced as unified. We thus have:
e1 at t: V-type + IP[V-type/B-type/A-type/I-type]
e2 at t: B-type + IP[V-type/B-type/A-type/I-type]
e3 at t: A-type + IP[V-type/B-type/A-type/I-type]
e4 at t: I-type + IP[V-type/B-type/A-type/I-type]
49 Translating, this tells us that e1 at t is a V-type experience, a token state that is inseparably fused with an inner perception of a unified total conscious state consisting of a V-type, a B-type, an A-type and an I-type experience; and similarly for e2, e3 and e4. And similarly, mutatis mutandis, for e2, e3 and e4.
50 To appreciate the holistic consequences of this way of looking at things let us temporarily assume that Brentano is wrong, and that experiential constituents such as e1- e4 are not in fact divisives that are incapable of existing independently of their actual wholes. Accordingly, let us consider a total experience E* which is exactly like E save in one respect: in place of the V-type visual presentation there is a V*-type visual presentation, which differs from the V-type in discernible ways. If we now try to characterize the total experience E*, consisting of the V*-type e1*, together with the unchanged e2, e3, and e4, we will have something along these lines:
e1*: V*-type + IP[V*-type/B-type/A-type/I-type]
e2: B-type + IP[V*-type/B-type/A-type/I-type]
e3: A-type + IP[V*-type/B-type/A-type/I-type]
e4: I-type + IP[V*-type/B-type/A-type/I-type]
52 Since, for Brentano at least, inner perceptions faithfully and infallibly reflect their presentations, the inner perception which features in E* will necessarily reflect the fact that E* contains a V*-type visual presentation in place of the V-type found in E. As soon as this point is registered, we can see at once that our starting assumption that the experiences e2, e3 and e4 exist in both E and E* collapses into incoherence.
53 In our original total experience E, a full description of the phenomenal characteristics of e2-e4 includes a reference to the accompanying inner perception: IP[V-type/B-type/A-type/I-type]. The (alleged) counterparts of e2-e4 in E* mentions a different and distinct inner perception: IP[V*-type/B-type/A-type/I-type]. The hypothesis that the same token presentations e2, e3 and e4 can be found in both E and E* results in a contradiction. Since we are obliged to ascribe different phenomenal characteristics to each of these token presentations in the total experiences in question we cannot coherently hold that they are numerically identical.
54 Evidently, the same reasoning can be applied to any part of any total experience. As a consequence, Brentano’s claim that presentations that are proper parts of more encompassing total experiences have the ontological status of divisives looks to be vindicated. The holism arises – to put the point more picturesque or metaphorical way – because on Brentano’s view our unified conscious states do not consist solely of presentations that are co-conscious with one another. Such presentations are also, in effect, reflected in a mirror (in the form of an inner perception) containing a representation of the entire unified ensemble. The singularly intimate relationship between inner perceptions and their presentations means that the representation of the entire unified whole enters into the phenomenal character of each individual presentation. Or in Brentano’s terms, it “contributes inwardly to their being”.
55 Resting as it does on some distinctively Brentanian theses – regarding the nature of inner perception, and the peculiarly intimate relationship that exists between inner perceptions and their objects – it will not be available to those who find these doctrines unpalatable. Nonetheless, since there is at least one other route to phenomenal holism, a route which only rests on the interdependencies generated by the relationship of “being experienced as existing together”, Brentano’s claim that experiential parts are divisives may well be on firmer foundations than has sometimes been assumed. 
See, for example, Galen Strawson’s “An Account of Four Seconds of Thought” in his Mental Reality (1994, § 1.7); all the references for the articles of this issue can be found below, p. 549.
It would be overly simple to assume that Brentano’s view that the soul had no place in the empirical science of psychology to conclude that he rejected the soul entirely: the projected (but unfinished) sixth volume of his Psychology was to have been devoted to the immortality of the soul – see Rollinger, 2012, for more on this.
In Dainton, 2008, chapter 9, I argue that holistic interdependence at the experiential level does in fact get transmitted to the systems of capacities which generate the experiences in question.
See Dainton, 2006, chapters 8 and 9; and Dainton, 2010.
For more on this form of holism see Dainton, 2006, chapter 9; and Dainton, 2010.
I here use Mark Textor’s translation of this passage; see Textor, 2006, § 4.
My thanks to Guillaume Fréchette for his helpful comments.