I would say the form of the oak is inherent within, immanent to, the acorn, and I think Aristotle thought the same. — Janus
What Aristotle shows is that there necessarily is a form (actuality) which is prior to the potential (matter) of the acorn. This would be the prior oak tree. The prior oak tree puts the form into the acorn, and the existence of the acorn, as the potential for another tree is dependent on the existence of that prior form, the tree, as cause, just like art is dependent on the artist who puts the form into the piece of art.
This would be similar to the which came first, chicken or egg question. When it is put in terms of "actual" (form) and "potential" (matter), Aristotle shows why potential is always dependent on a prior actuality, so actuality is necessarily first. This is known as the cosmological argument, and the Christian theologists have adopted this necessary, prior actuality, as God.
The ensuing issue which is evident, is that from the materialist/physicalist perspective, we look at the temporal existence of physical objects, and we realize that in every case the potential for the object precedes the actual material existence of the object. The simplistic, monist, inclination tends toward the conclusion that potential is prior to actual, because of this materialist/physicalist perspective which inclines us to think in this way. Furthermore, our conceptions of time tend to bind time with physical/material actuality. This allows the materialist/physicalist to simply assume an unintelligible origin to material existence, as the potential for actual material existence is represented as prior to time.
The problem with this materialist/physicalist, monist, perspective which Aristotle demonstrates, is an issue with the nature of "potential". Potential provides the possibility to be actualized in a number of different ways. Not any single, specific actuality is necessitated by a condition of potential. But since there is in reality, one specific and particular actuality which proceeds (we might say emerges) from any condition of potential, we need to assume a cause of that particular actuality. There is a reason (cause) of why one particular actuality is derived from any condition of potential, rather than some other particular actuality. This is known as the contingency of material/physical existence. "Contingent existence" means that the particular material object which exists was necessitated by a cause. It is contingent on a cause. This cause is the necessary actuality, and the need to assume such an actuality negates the possibility of potential being prior to actual, in an absolute sense.
ou seem to be claiming it is something "abstract" that comes from "somewhere else". I don't believe Aristotle would agree with this (although Plato might, depending on how you interpret him). — Janus
What I am claiming, is what Aristotle actually painstakingly demonstrates. The prior actuality, which comes from "somewhere else", is not properly represented by spatial terms. In his "On the Soul" the soul is described as that prior actuality. And, he makes an effort to show that it is a mistake to represent this immaterial existence in spatial terms. In his "Metaphysics" he demonstrates why it is necessary to assume an actuality (Form) which is prior to all material existence (cosmological argument).
Today we know about something Aristotle didn't: DNA. So, the form of the oak is encoded within the DNA in the acorn. But that DNA comes from previous oaks, and there is no reason to think the DNA itself has not changed, evolved, over time from ancestor trees, precursors to the oaks and other types of trees that evolved along different lines.. — Janus
Don't you think that the presence of DNA requires a cause? If "DNA" represents the potential for a living body, and DNA exists as an actual material form (itself a material object), wouldn't you think that it's reasonable to believe that there is a specific cause of this particular and unique material object?
Suppose that prior to the existence of DNA there is some sort of "matter" which would serve as the potential for DNA. This matter would have to have a particular form to serve as that potential. Then we would have to assume another potential as prior to that form. As we proceed in this way, to avoid infinite regress, and also to properly represent the reality of the situation, the "potential" involved becomes more and more general, providing a wider range of possibility. So each time we step backward in time, toward the original material condition of possibility, the range of possibility gets greater, approaching infinity as the limit, in the manner of calculus. Consequently, the materialist perspective is to assume an original infinite potential (in Aristotelian terms, prime matter).
The cosmological argument shows the deficiency of this perspective. What happens, is that when we look backward in this way, toward the wider and wider range of possibility, the cause which 'chooses' to actualize this particular actuality rather than some other, becomes more and more important, as providing significant and very important direction. So the actuality which corresponds with this proposed possibility becomes more and more significant, in the sense of important or meaningful. In the case of your example, DNA, you can see that the actuality which 'chose' to create DNA, and not something random, is extremely significant. As we approach the limit, the proposed infinite potential, the magnitude of potential (number of possibilities) would get so high, and coincident to that (to provide the reality of that very high degree of possibility), the level of actuality must be conceived of as extremely low. However, the first step, of that actualizing cause, to go in the required direction, is at a correspondingly high (approaching infinite) level of importance, and this is not provided for by that extremely low level of actuality, logically necessitated by the high magnitude of possibility.. So the idea of that extremely important actualizing first cause, coming from that very low degree of actuality provided by the almost infinite potential, becomes just as highly (approaching infinity) improbable.