The second volume of Husserl's Ideen (publication withheld until 1952) is the work of many hands. Husserl was dissatisfied with it and did not publish it. The first draft was written very rapidly in 1912, immediately after the manuscript of the first volume was completed. Husserl added material in 1915, and turned it over for editing to his assistant Edith Stein, who had come with him to Freiburg from Gottingen. Stein transcribed the work from Husserl's shorthand in 1916. He gave her further material, and in 1918 she produced a collation arranged and titled as at present: the constitution of material nature, of animal nature, and of the cultural world. But Husserl's phenomenology was evolving, and the manuscript did not suit him. Another assistant, Ludwig Landgrebe, worked on it 1923-25, and Husserl himself edited it in again 1928. It finally came out posthumously.
If the pursuit of unity had guided Husserl like a north star from his earliest writing on through the discovery and first articulation of phenomenology, then in Ideen II that star becomes obscured by "light pollution" from numerous more recent and competing insights. Without access to the manuscripts, it is impossible to know with precision how that came about. In portions of the text as we have it, the concern with unity remains a significant factor.
However, other portions seem to go against the grain of key insights from the first volume and the earlier works. For example, in LU and Ideen I, the material sphere had comprised states of affairs; that is, facts or cases such as could be expressed in logical propositions. There were indeed "things" in there, such as roses, yet the emphasis was upon the factual scenarios into which these things figured. By contrast, in Ideen II "material nature" is populated with substantial items, and the fact they are embedded in circumstances has to be additionally stipulated, almost as an afterthought (# 15c). By the same token, in the earlier work the eidetic sphere had comprised the forms of logical propositions and the rules of inference. While there were indeed "essences" entailed there, nevertheless the emphasis fell upon the lawful patterns of thinking about being. By contrast, in Ideen II "animal nature" is populated by psychic items whose unity is analogous to that of physical things yet whose active engagement with the latter can hardly be explained.
This shift matters, because judgments and perceptions reach unity in quite different ways. To certify that one selfsame proposition (e.g., that the cat is on the mat) returns to our consciousness on several occasions is quite a different task than to certify that one selfsame substantial entity (e.g., this mat-loving cat) returns to our sight every afternoon. Husserl's early discoveries about unity had to do with judgment, and they were based upon the lived difference between synthetic judgments and analytic judgments. His ambitions then were not primarily metaphysical or epistemological. Moreover, it is relatively easy to "feel" the difference among three sorts of judgment: (a) a synthetic judgment that arbitrarily groups several items together, (b) a synthetic judgment that groups things in recognition of some characteristic that all share independently of the judgment, and (c) a judgment that the unity imputed to a thing is not owing to judgment at all. The distinction among these judgment-forms was already established in the Habilitationsschrift. However the task undertaken in Ideen II is forcibly to transpose that distinction onto perception, and so to come up with a general test for certifying when knowledge is genuinely in touch with reality.
This project is set in motion in # 9, where new terminology is introduced for the threefold distinction first made in "Begriff der Zahl." (However, now that the transcendental reduction is presupposed, the arrow of causality should be removed. There can be only correlation or its absence.) BZ's "psychic relation" now becomes "categorial synthesis," in which perception serendipitously collects disparate items into one group, for no special reason intrinsic to the items. BZ's "content relation" (or "physical relation") becomes "aesthetic synthesis" (or "sensuous synthesis"), in which perception recognizes some intrinsic reason for grouping these items and finds itself constrained to do so by something other than mere whim. And BZ's uncomposed unity (e.g., "that rose there") becomes the "pure sense-object."
In BZ, "synthesis" meant a combining judgment: a judgment that erected a set of things with many members. A set with one member–that is, a unified thing–obviously needed no synthesizing judgment to set it up. In Ideen II, however, "synthesis" means a perception that, while receiving multiple impressions (the off-shadings or Abschattungen), composes an object out of them. But this object is a unity, not a group; in fact, it is what Husserl would earlier have called an uncomposed unity. In other words aesthetic synthesis–operating now over partial views, not discrete items–finds that it has a reason for referring those multiple impressions to one object, even though the unity of the thing never gives itself directly to consciousness. What is that reason? This question is enticing, because Husserl is tantalizingly close here to describing a way in which the real unity of things is available for knowledge.
Husserl works on this question in # 15b, where "the spatial body is a synthetic unity of a manifold of strata of 'sensuous appearances' of different senses" (42-43). The spatially extended thing is a unity drawing together all the experiences we have had of it, and summoning us toward further experiences of it through sight and touch and our other senses. It achieves its unity as a spatial location, which seems not to depend upon whether or not it is actually perceived.
However, Husserl cautions, this unity alone is insufficient to validate itself. He writes:
"(W)e have first taken the body as independent of all causal conditioning, i.e., merely as a unity which presents itself visually or tactually, through multiplicities of sensations, as endowed with an inner content of characteristic features…. But in what we have said, it is also implied that under the presupposition referred to (namely, that we take the thing outside of the nexuses in which it is a thing) we do not find, as we carry out experiences, any possibility for deciding, in a way that exhibits, whether the experienced material thing is actual or whether we are subject to mere illusion and are experiencing a mere phantom" (43).
Thus, reality is not guaranteed for an isolated item, even when it seems to be giving us a reason to take it as the unified core attracting its manifold appearings to one hub of reference. The central location of the thing is dependent upon its real circumstances, as Husserl goes on to say in # 15c. The reality of "one" depends on "others"; i.e., on thing-connection. The thing is what it is in relation to its surroundings. This becomes apparent when things move and change, for their changes must correlate coherently with reciprocal changes in the things next to them.
Such co-variance is what certifies reality–or materiality, which Husserl seems to equate with it. In # 15c, reality means substantial causality. Within the webwork of material things, everything affects everything else. The real is the causal. Co-variance across the material realm, then, is what certifies the oneness and reality of that realm (# 15e).
Animated bodies also connect in the webwork of material things (# 13). Each of them is a center of appearings, a one, just as every other thing is. However, unlike soulless bodies, each animal is also a zero. It lives at a point of origination. The animal body bears the zero-point of orientation for the pure ego (61), as its absolute "here" (135, 166). Arithmetically, this is a stunning contrast. Every "something" whatsoever is either a one or a one-and-one-and-etc. But the animated body, in addition to being just one of those somethings, is also the one who is zero: the one from whom the counting starts, the one who chooses whether and where it is appropriate to insert the and's.
But any series that is initiated by/at/in the living body is counted off nonarbitrarily. Such series go in order; they are "motivated." This is owing to the movement of the body itself within the material web. The body's own kinesthetic sense will coordinate with the corresponding changes in sensory perceptions as it navigates among things. Thus, the zero shifts position in relation to the other unified centers to which perceptions accrue; but as it does so, the series of their appearings change in a regular way (63).
What about counting zero's? Are they multiple; are there many human bodies? Husserl declines to pursue this avenue of approach into the problem of other minds and human community. Intersubjectivity will treated instead as an implication of the reality of the material world, not a precondition for it. The multiplicity of bodies is taken up only on page 83, where it is admitted that the foregoing analysis has been framed on the assumption that there would be only one, "solipsistic," point-zero in reality. Belatedly, other bodies now are brought into the picture–but not because they are necessary for its unity, or because they have been apprehended among the realities presenting to consciousness. The others are brought in because they are required for the full unification of the thing in reality, whether that thing is one of the physical bodies or my very own live body. To be is to be describable (87). Reality for the thing entails a possibility of appearing to anyone at all. Being counted from one zero-point is not enough for the real thing. To count, it needs the possibility of being counted from multiple directions.
The thing is a rule of appearances. That means that the thing is a reality as a unity of a manifold of appearances connected according to rules. Moreover, this unity is an intersubjective one…. The physicalistic thing is intersubjectively common in that it has validity for all individuals who stand in possible communion with us (91-92).
To be real, the thing must count as a place or location, a center, independently of any particular point of origin. Yet what grants reality to the thing is not some consensus reached by observers. Indeed, the thing may look entirely different to different observers; however, its reality constrains all to agree that, at least, "it is there." Oddly, then, the real thing is another kind of zero, for its barest reality consists in its being an empty place-holder (91-93).
Finally, Husserl makes unity a synonym for the philosophical term "substance" as traditionally meant. For example, he says that both the soul and the body are unities, so that an analogy obtains between psychic unity and material unity (129, 131). Oneness becomes the ontological form that determines substantial reality (133). The pure ego is one with respect to an individual stream of consciousness, that is, before the transcendental reduction has de-individuated the latter (117); however the pure ego is insubstantial and not one whenever the reduction is in effect (128).
And so Husserl's quest for unity splinters and spends itself out by diverting into many contradictory projects pursued by the many unharmonized voices of Ideen II. Although the manuscript remained unpublished, it was made available for consultation by a number of Husserl's younger colleagues. Among the last publication of Husserl's lifetime was the Cartesian Meditations of 1931, in which he addressed the apparent solipsism of his transcendental phenomenology. That work itself was undergoing a comprehensive reworking in partnership with Husserl's assistant Eugen Fink during the years before Husserl's death in 1938.
Husserl's publications and his extensive Nachlass are being brought out in a multi-volume critical edition entitled Husserliana – Edmund Husserl, Gesammelte Werke, from Nijhoff in The Hague. The major works published during Husserl's lifetime are the following: