In the upcoming analysis of house division in Hellenistic astrology, we will be making a new distinction for which there is as yet no accurate terminology. Sometimes we will be talking about a twelvefold division done for the purpose of ascertaining planetary strength; we will usually call such a division a "dynamical" division. At other times we will be interested in a twelvefold division done for the sake of establishing regions that are associated with areas of life houses in the modern sense; we will call such a division a "topical" division. This latter is a useful word because it derives from the Greek word topos that simply means place (that is, a place relative to the Ascendant). However, this Greek word also acquired the mean of a "topic" or issue in the modern sense; for instance, Ptolemy often calls the chapters of the Tetrabiblos that deal with specific issues such as parents, the shape of the body, etc., "topics."
One of the earliest uses of zodiacal divisions for special topics or areas of life is in a work that antedates the root text of Nechepso/Petosiris. It is called Salmeschoiniaka and has to do with the decans. Only fragments of this work survive, but fortunately a piece quoted by Hephaistio employs the decans as places having governance over special issues. (II 18) 
"One must also examine the decans since the first one of the Horoskopos deals with birth; the 28th from the Horoskopos, which culminates early, deals with livelihood; the 25th, which culminates at noon, deals with sickness; the 9th, which rises late in the east, deals with injury; the 17th, which rises in the west, deals with marriage and wife; the 8th, the door of Hades, deals with children; the one in the subterraneous [pivot] deals with death." (II. 18).
Since the decans are clearly understood to be related to divisions of the signs, this might be called a whole-decan system of houses.
Possibly contemporary with this is the dodekatropos (or "twelve-turning") attributed to Hermes. This is mentioned in the epitome of Thrasyllus and in Rhetorius; it also seems implicit (although Hermes is not mentioned) in two places in Valens and in the discussion of Maternus in Book III, chapters 2-7. In all of these cases the twelve places (or houses, to use the somewhat misleading modern term) are unequivocally coincident with the signs. Nowhere in the earlier writers have we found an equal house system from the Ascendant degree or any system of mundane houses (such as those based on the division of the mundane quadrant). Many of them, such as Dorotheus, do not even address the issue. They simply talk about the Horoskopos and the Midheaven and places relative to these. Their failure to treat the issue thematically is an indication that house-division was a convention so much taken for granted that it need not even be addressed. In that case, the few who do give clear indications of a whole-sign system can be taken as representative of the general practice.
Although later than Ptolemy historically, Valens represents the earlier tradition uninfluenced by the Tetrabiblos. In the considerable amount of translation we have done from the Anthology so far, we have found a consistent use of whole-sign houses, with two apparent exceptions, which we will now deal with.
In Book III, chapter 2, he discusses a division of the mundane quadrant into three equal pieces (later called the Porphyry system). However, it is perfectly clear from context that his intention there is to determine the places in which the planets may be most and least active. He in no way indicates that he is establishing a division into topics, or a house-system in the proper sense. In fact he makes it clear that he is not when discussing the second place so constructed, "and to judge another 1/3 part of the degrees as middling neither more good nor more base on account of the post-ascension of the Horoskopos and the Goddess and the diameter of God." Now, the post-ascension of the Horoskopos is the second whole-sign, while Goddess is the traditional name for the third whole-sign. In other words, this division has an intermediate activity level because the two second and third traditional whole-signs overlap on it. Notice that he does not reassign the name "post-ascension" to the second interval nor the name "Goddess" to the third interval of his new mundane division.
Furthermore, Valens offers this assessment of activity levels as his own correction of a tradition that preceded him, in which the first 1/3 of the mundane quadrant was considered to be powerful,but all the remaining degrees weak. Thus, it may have been Valens first of all who extended the activity assessment to twelve places instead of eight, and such a system could not in that case have preceded him.
The second apparent exception to Valens's otherwise perfectly consistent use of whole-sign houses occurs in Book IX, chapter 3, and it is indeed puzzling. It is in this chapter that Valens introduces the well-known procedure of "turning the wheel" to derive additional meanings of the houses from the basic ones. He explicitly calls this a "twelve-turning," as we said above a method attributed to Hermes, so this passage too apparently preserves the earlier tradition. Now, in his detailed delineation of this system he explicitly mentions (and frequently implies by gender) zoidia. He also employs the traditional topical names such as Good Spirit, Goddess, etc. Thus, this too is a whole-sign system. The problem occurs in a paragraph immediately following this treatment, which I translate here:
"But before all it is necessary to reckon the places to the degree. And at least whenever the degree of the Horoskopos may be grasped, it is necessary to count from that degree up until the 30 degree completion of the next zoidion. And that will be the place concerning life. Then similarly up to the completion of another 30 degrees concerning livelihood; and the next as before. For often two places falling together onto [or coinciding on] one zoidion foretell both species in accordance with their distances in degrees. And similarly, it is necessary to examine the lord of the zoidion, in what zoidion it chances to be and to what sort of place it holds fast, according to its canonical description in degrees. For in this manner the procedure [or perhaps turning] will be judged. And if someone would reckon platically at one place per zoidion (which is rare), they [the natives? the places?] encounter constraints and outrages, or the entanglements of matters."
I am not the least bit confident of this translation. For example, I am not sure which two places he is referring to in the middle of the paragraph. It could be two places in the style of equal houses from the Ascendant overlapped by one zoidion, but this would contradict his own clear employment of whole-signs in the delineations immediately preceding; it could also be two derivative places (say, the perfectly coinciding on one zoidion) which would be consistent with context but render the last two sentences uncertain. I am not even sure about the meaning of the algorithmic clause, "it is necessary to count from that degree up until the 30 degree completion of the next zoidion." But I will spare the reader all the gory details.
In the midst of all this confusion, and assuming that Valens does have in mind some system of equal zodiacal division based on the Ascendant degree, let me make a speculation based on Valens' use of lots which may provide us with an important clue about the relationship between whole-sign houses and equal divisions from the Ascendant. It is intrinsic to his treatment of lots that they may be regarded as "Horoskopoi," or quasi-ascendants; that is, they can become the first houses of derivative whole-sign systems, the meanings of these signs in succession being analogous to those in the basic natal chart. The only real difference is that the fundamental whole-sign system is regarded as more general, while the derivative system is intended to yield greater detail. Nevertheless, they are conceptualized in the same way.
Now, the lot itself occupies a degree somewhere in the sign destined to become the first house of a derivative system; the presence of the lot must be thought of as somehow altering the very sign in which it falls, making it an appropriate first house for that of which it is the lot (the father, for instance). Similarly, the sign in which the Ascendant degree falls becomes the first house of the general whole-sign arrangement; the Ascendant degree is a kentron, a pivot or hinge around which the sign turns, and it is this pivoting that alters the sign and makes it serve the role as the first whole-sign, wherever the Ascendant point may fall in the sign itself. Might not the first degree of each equal "house" from the Ascendant be regarded as the "pivot" of the whole-sign in which it occurs, a kind of point around which it turns and which makes the entire sign the second place (or house), for instance, giving it its unique character? Thus, the "twelve-turning" would be an extension of the idea of a pivot, formerly restricted to the angles, to all the intermediate signs.
In conclusion, if this interpretation has any merit, every degree which is thirty degrees from the Ascendant or a multiple thereof should be regarded as a "cusp" (or turning point) of the whole-sign in which it occurs albeit not a cusp on one of the extremities of the sign. It would also follow that the intervals between these degrees should not be regarded as houses at all. Such an equal house system in the modern sense would be a misinterpretation of the original purpose behind the equal division of the zodiac from the Ascendant, which was to establish the turning points within the signs themselves. It is interesting to note that Maternus is the first author we know of who explicitly uses an equal house system from the Ascendant (in Book II, chapter 19, even though he elsewhere uses whole-sign places relative to the Ascendant, as in Book III, chapter 2). He is two hundred years after Ptolemy and Valens. Might he have misunderstood the earlier tradition? It is at least very interesting that he uses the word cuspis for the first degree of each of these houses, for the word cuspis, meaning point, and cardo, meaning hinge, are both fairly good translations of the Greek word kentron, which seems to contain both the Latin meanings.
Before we leave Valens, there is one final point to make. Just prior to his discussion of the "twelve-turning," he mentions an "eight-turning," which was apparently used by Nechepso/Petosiris. The nature of this system is still somewhat mysterious. However, from the context we could say that it too was coincident with some divisions of the zodiac rather than defined by a bisection of the mundane quadrant. As a guess, I would point out that in ancient times the signs were not only divided into three with the decans, but also into two with the "steps." Thus, just as each whole-sign house consisted of three decans, so each eight-fold division may have coincided with three steps of the zoidia.
Ptolemy is regarded as the author of a special equal house division that begins five degrees above the Ascendant, and it is now widely assumed that this was his preferred system. However, three things need to be pointed out here. First of all, prior to Book III, chapter 11, the discussion of length of life, there is no reason to believe that Ptolemy regards the Horoskopos, Midheaven, etc., as anything other than whole-sign houses. He uses all the traditional language of pivots, post- ascensions, and declines. In Book III, chapter 6, dealing with siblings, he explicitly calls the place of the mother a zoidion and invokes the tenth place relative to this in the traditional manner of a derived house system. He does not introduce any house-system whatsoever in his first book, which deals with the elements of astrology. Finally, he never says that he will be describing his house system in an upcoming chapter, though he does say this in the case of the Lot of Fortune and certain other matters. We have no evidence of this particular system prior to Ptolemy, and if he was innovating, we would expect him to say so when the issue arose.
The second point is that when he does introduce his system in Book III, chapter 11, it is in a very specific context of length of life calculation. The problem is to determine the "places for releasing," that is, the places where the releaser (or hyleg as it was later called) must be in order to qualify for that role. The implication is that the places he lists are places where the planet will possess the greatest activity, as is only suitable for such an important signification as length of life. Accordingly, he says, "for one must properly refuse the whole region under the earth so great an authority." As places (or houses), several of them, such as the seventh, ninth, and eleventh, have no immediate topical connection with the issue of life. So it seems that the zodiacal division he describes is not for the purpose of establishing houses per se.
Third, one of the earliest commentators on the Tetrabiblos, Pancharios (as quoted by Hephaistio), did not think that Ptolemy had in mind an equal house division of the zodiac at all, but rather a mundane style house system similar to the one mentioned above in the discussion of Valens, the only difference being that he accommodates the five degrees above the Ascendant unequivocally required by Ptolemy. Since Valens introduced almost exactly the same system for the clear purpose of making distinctions of planetary activity and not of topics, we may surmise that this is Pancharios intention as well. As I have pointed out in my notes, Pancharios evidently had a different text at his disposal that allowed him to make this interpretation (by inference, as he himself concedes).
If someone wished to argue that Ptolemy did indeed regard his division as a topical house system in the fullest sense, the strongest piece of evidence in his favor would be the passages in chapter 11 where he seems to call his new divisions by the names traditionally used to designate whole-sign houses, such as Evil Spirit, Good Fortune, etc. However, as I have argued in my commentary on that section, there are at least two other ways of reading the passage in question without assuming that Ptolemy is transferring house names to his own division. And from the number of manuscript variations at key points in the text, it appears that a number of readers and copyists were in doubt on exactly this issue. I should further mention that all these house names are so loosely connected to the basic syntax of the sentence that they could even have been interpolated by a later editor; they are present in the text that Hephaistio quotes and may have present in the text of Pancharios, although this cannot be inferred for certain from Hephaistio himself.
One final remark: If Ptolemy did intend to use an equal house system originating five degrees above the Ascendant, he clearly did not mean it to establish house cusps of a whole-sign system in the manner of our speculation above. Rather, it was the intervals in between that were of interest, as would be only natural in the case of the determination of planetary strength. And if he furthermore did apply the traditional house names to his new divisions, this would mean that the two different but equally fundamental prototypes of house division other than the whole-sign model (for the sake of establishing planetary activity and the cusps of whole-sign houses, respectively) have been fused together into one hybrid system.
Paulus still uses whole-sign houses exclusively in his topical delineations, despite his admiration for Ptolemy, as if he did not regard his equal house division as topical at all.
From Hephaistio's remarks, it is clear that most of his contemporaries, Pancharios notwithstanding, did regard Ptolemy's system as a topical equal house system beginning five degrees above the Ascendant, which is still a common interpretation today. However, Hephaistio seems to favor Pancharios' interpretation based on a modified trisection of the mundane quadrant, as does Porphyry, and finally Rhetorius (although he does report the "twelve-turning" of Hermes). There is no evidence that any of these three attempted to turn this dynamical division into a topical system.
Maternus, as we have already mentioned, uses an equal house system from the Ascendant topically, although elsewhere he uses places relative to the Ascendant sign.
If the above analysis is correct we can draw several conclusions. First, since it is apparent that no astrologer writing in Greek ever used a dynamical division topically, we will have to look to the later medieval tradition to see when this transference took place. Furthermore, we should view such a move with great suspicion since it most probably was based on a misinterpretation of the earlier tradition. Of course, it is always possible that this was a creative misinterpretation that accidentally had some truth to it, but at the very least we should bracket the use of mundane houses topically until they could be verified in some experimental manner. However, we are still left with the problem of the correct dynamical division, though here the Gauquelin data may be of some assistance.
Secondly, somewhere along the line the cusps themselves (which originally fell somewhere in the signs themselves and were employed to determine the turning points of these same signs) came to be understood as the boundaries or extremities of the houses a misunderstanding that began even in Greek times. The cusps in the dynamical division evidently underwent the same transformation. However, we might even speculate that the mundane cusps, or cusps of a dynamical division, might also be interpreted as giving a special dynamic character to the signs in which they occur, a character different than the topical. This may connect with the ancient doctrine of the profitable places (or prospering places as we are now translating), which were the signs in which the planets had enough activity to conduct their business, or in which they could be used oracularly depending on how we interpret the ambiguous term chrematistikos. Here too we should look to the later medieval tradition to see how this second misunderstanding came to be taken for granted.
A metaphor may help to join all these speculations together. We may imagine that the cusp within the sign gives a certain characteristic "curvature" to that sign that qualifies it to be the second, third, etc., whole-sign house. The different possible positions of the cusp within the sign do not change the fundamental type of curvature given to the sign; they only modify it within this species, just as there are different individual hyperbolas, each having a unique curvature, that all have the defining characteristic of a hyperbola. The present of a dynamical cusp in a sign modifies it in a different manner, giving it a certain size, for instance, magnifying or reducing it. These topical and dynamical cusps together absolutely determine the "curvature" and "size" of a given sign.