Towards the end of his commentary on section IV, chapter II of the Kitab al-Isharat, the Ash’arite theologian Imam Fakhr al-Din al-Razi presents what I think is a quite intriguing, even markedly modern, objection to the Aristotelian notion of the final cause. Specifically, Imam Razi’s shakk is directed at Ibn Sina’s thesis that the final cause is a cause, through its quiddity, of the causality of the efficient cause. Before dealing with Imam Razi’s objection, a few words are in order about some of the points Ibn Sina sets down before the discussion of the issue in question. Doing this may be of some help in understanding Imam Razi’s critique.
Generally, section IV is a discussion about existence and its various causes; specifically though, chapter II concerns the nature of the four causes i.e., the material, formal, efficient, and final. The Shaykh al-Ra’is begins by noting that a thing may be caused either in its quiddity/essence or in its existence. (That existence and quiddity are distinct constituents of a thing has been established elsewhere). He then gives the example of a triangle to make the point: its essence is caused by a plane and three straight lines; taken together, they can be said to be constitutive of what-it-is i.e., its quiddity. The plane or two-dimensional space is as if it were the material cause of the triangle and the three lines serve as the form of the triangle. As for the the existence (in extra-mental reality) of the triangle, it must be held to have causes other than the matter and form. These causes are the efficient and the final. They are in no way constitutive of the essence of the triangle and are accordingly not, unlike the matter and form, included as parts of its definition.
From the above considerations, it becomes evident that one may understand the concept of something and but still remain uncertain about whether or not it is instantiated i.e., whether or not, as the Shaykh says, “concrete existence is to be attributed to it.” Again, this is because, given the distinction between essence and existence, and the different causes involved in the production of each, what you know to be a certain line and plane i.e., the triangle, you may not necessarily know to have a concrete i.e., extra-mentally existing, individual instance. Now in things which have causes constitutive of its essence, like the triangle, the efficient cause of its existence will be a cause of either one of the constituents of its essence e.g., only the form, or it will be a cause of them all e.g., the form and the matter. As for the relation of the final cause to existence – the main focus of Razi’s attack – Ibn Sina says that the final is the cause of the causal efficacy of the efficient cause. In other words, the final cause is what causes the efficient cause to be causally efficacious i.e., to act and produce effects in external reality. At the same time however, the final cause is also an effect of the efficient cause. This means that if the final cause comes into existence, the cause of its (coming into) existence will be the efficient cause, but the efficient cause, unlike the final with respect to the efficient, ought not to be thought of as the cause of the final causes causality. Therefore, to put it more technically, in terms of its quiddity – defined as ‘that for the sake of which a thing is’ – the final cause is the cause of the causality of the efficient cause, and in terms of its existence (in external reality), it is an effect of the efficient cause. The reason for this latter point, as Imam Razi explains, is “because the efficient cause moves only in order to realize [a] purpose and end.”
Having said all that, here then, quoted in full, is Imam Razi’s objection to Ibn Sina’s view of the nature of the final cause; in particular, that it’s somehow a cause of the efficient cause:
Someone might say: There are several problems implicit in your theory that the final cause is a cause, through its quiddity, of the efficient cause, because you are foisting the final cause onto natural acts and natural potentialities that possess no intentionality or consciousness whatsoever. The final cause’s quiddity here [i.e., in things whose acts lack intention or consciousness] cannot be said to exist in the mind because in this case there is neither mind nor consciousness; yet [the final cause] does not exist in the outside world because its existence in the outside world is the effect of the efficient cause. If this is so, [the final cause] will be an absolute non-existent, and no absolute non-existent can be a cause of an existing entity. So how can the efficient cause’s causality be by virtue of the final cause’s quiddity? The only option is to say natural acts have no ends, but this is contrary not only to [the Peripatetics’] doctrine but also what he [i.e., Ibn Sina] himself ascertained in Physics I of the Shifa’.
Put syllogistically then, Razi’s argument for why things without intentionality or consciousness have no final causes seems to be the following:
Major: For the final cause to be a cause, it must either exist in the soul (mentally) or outside the soul (extra-mentally). Minor: But in things with no intention or consciousness it exists in neither way. Conclusion: Therefore, in such things it has no existence at all and so will not be a cause.
Proof of the major: this premise is implicit in Razi’s argument and so he does not offer any explicit proof of it (at least not here). Nonetheless, his point I think is reasonable and clear enough: he is arguing that for something to have any causal efficacy, it must exist, and a thing, if it exists, only does so either in the mind or outside it. There is no third option. This is an important premise in Ibn Sina’s philosophy and so I think he’ll whole-heartedly concede it.
Proof of the minor: in things which act without intention or consciousness, as for the final cause existing mentally, “[its] quiddity here cannot be said to exist in the mind because in this case there is neither mind nor consciousness.” And as for the final cause existing extra-mentally, “[it] does not exist in [such a way either] because its existence in the outside world is [supposed to be] the effect of the efficient cause.” That is, it does not exist externally yet because on the present assumption the efficient cause has not yet acted – for there isn’t any end in a thing which lacks intention or consciousness to move it to fulfill such a presumed end. And the conclusion i.e., that “[the final cause] will be an absolute non-existent, and [as such it cannot] be a cause […]” in things whose acts lack intention or consciousnesses, follows.
Given these considerations then, it seems one ought to hold, with Imam Razi, that “natural acts [i.e., actions which involve neither intention nor consciousness] have no ends [i.e., final causes].