In a recent conversation, I was asked about the difference between a Dinlogun (caracoles) reading and an Ikin reading. The question was actually a far mor nuanced, and politically laden one than it appears at first blush. What they were really interested in was why, if one has kariosha and Ita, in which "odu" are drawn is there a need to go to Ifa, and what are the differences? This of course is a bit of a minefield of a question, and to some extent depends on your "acceptance" of Ifa as a part of the Orisa arcana and Orunmila as the Orisa of knowledge and divination.
Approaching this from the most literal sense first requires us to understand the type and style of divination performed. Irrespective of whether Dinlogun is a subset of Ifa, is the issue of whether the diviner is actually pulling Odu or not. Dinlogun, contrary to popular belief, is actually not accessing, nor pulling Odu. We know this for three simple reasons. First, while some of the names for the patterns in Dinlogun match to Ifa Odu, not all of them do. The implication here is that there may be a link, but the two are definitely not the same (Ejioko, ejila shebora). Further, the names for 13 and up (metanla etc) are just the yoruba names for numbers. Second, the double throw is something that is a newer system, part of the lucumi system, and in Nigeria single throws the norm for dinlogun. It's only recently that Oriate began referring to Odu in the same way Awo Ifa do, in both books by early Oriate such as "manual de oriate" by angarica, the combination throws would be for example referred to as "oche tonti oche" not Oshe Meji etc. Clearly, with more access to Ifa texts Oriate have moved to usurp power away from Babalawos, whether right or wrong, that's not the question here.
Lastly, and most importantly, the reason dinlogun is not pulling Odu is that the dinlogun does not go through the process of being birthed from Odu (the wife of Orunmila) and its priests have not undergone the initiation of seeing Odu. This is not, in truth, meant to belittle dinlogun reading, but to clearly differentiate it from Ifa.
Approaching this from a more philosophical and theological perspective, dinlogun are the mouthpieces of the Orisa and as such are meant to be a way for Orisa priests to access the knowledge of the Orisa for which they were consecrated. In other words, Sango's dinlogun, when consecrated to Sango, are meant to be a way for his devotees to access his wisdom and knowledge in particular. As is the same for Esu, Yemaya/Yemoja, Oshun, etc etc etc. This is EXTREMELY important to understand as when you are getting Ita, you are becoming a priest of a particular Orisa, and in doing so, need to get the advice of that particular Orisa.
This is in sharp contrast to the Ikin Ifa on several different levels. First, Ikin Ifa are not consecrated to Orunmila, but are consecrated to Ifa. While Orunmila is an Orisa, he is an Orisa of a different sort, as even Orunmila is a priest of Ifa, albeit the Orisa that created the system that made it possible for us as humans to access the wisdom of Ifa. Where even bigger differences occur that separate Ikin from Dinlogun are in the process of accessing Ifa.
It's first important to understand what Ifa is, and as I understand it, Ifa is the codification of the wisdom/knowledge of the world, past, present and future, as handed down by Olodumare. Based on that premise, Ikin is not accessing Orumila (meaning it is not the mouthpiece of the Orisha, as is the case of Dinlogun), but petitioning Orunmila (and importantly Esu) to help in the process of accessing Ifa. This is done through Odu, Orunmila's wife. Odu the wife, gives birth to the Odu that appears on the Opon Ifa as marked by the Babalawo. This process, requires an esoteric and metaphysical union of male and female energies to give birth to Odu Ifa. It is then the job of the Babalawo, who has undergone training, in addition to initiations in which the secrets of Odu are revealed to him, to interpret this for the person who is seeking advice.
As an aside, the Ori of the seekers is consulted during the D'afa (divination) process through the Ibo. An extremely important process because Ifa could be seen as the infinite number of conversations happening simultaneously, and it's only through the Ibo and presence of Ori that the Odu that is appropriate for the seeker of advice is "tuned in" to.
Understanding the full process of Odu (of which I've only gone through a small portion) is what gives light to the understanding that Odu Ifa accessed through Ikin are indeed quite different from Dinlogun. A. Caracoles are the mouthpieces of the Orisa and Ikin access the wisdom of Ifa. B. Odu the wife of Orunmila gives birth to Odu on the Opon Ifa, which does not happen with the caracoles. C. Non-Ifa priests do not go through Itelodu, and therefore have not been initiated to the mysteries of Odu, and only Ikin are born from Odu. D. All Orisa, from Oshun to Sango to Orunmila himself consult Ifa when they are looking to find clarity in their path. Ifa is not meant to supplant Dinlogun, but complement it. There are moments when as an Olorisa you need to consult the Orisa to which you were initiated, then there are moment when you need to clarify the larger picture, where just like all the Orisa, you go to Ifa for advice.
-- marcos Ifalola sanchez