## 1. Introduction



Aristotle was not the first thinker to engage in a causal
investigation of the world around us. Quite the opposite: from the
very beginning, and independently of Aristotle, the investigation of
the natural world consisted in the search for the relevant causes of a
variety of natural phenomena. From the *Phaedo*, for example,
we learn that the so-called "inquiry into nature"
consisted in a search for "the causes of each thing; why each
thing comes into existence, why it goes out of existence, why it
exists" (96 a 6-10). In this tradition of investigation,
the search for causes was a search for answers to the question
"why?".



Both in the *Physics* and in the *Metaphysics* Aristotle
places himself in direct continuity with this tradition. At the
beginning of the *Metaphysics*, Aristotle offers a concise
review of the results reached by his predecessors (*Metaph*. I
3-7). From this review we learn that all his predecessors were
engaged in an investigation that eventuated in knowledge of one or
more of the following causes: material, formal, efficient, and final
cause.



However, Aristotle makes it very clear that all his predecessors (no
one excluded) merely touched upon these causes (*Metaph*. I 7,
988 a 22-23). He equates them to boxers who lack boxing
technique: while sometimes they can throw a nice punch, any punch that lands is only a lucky one (*Metaph*. I 4, 985 a 10-19). In other
words, even when his predecessors had valuable insights into
causality, they spoke without having proper knowledge. His view is
that they spoke about causes without making the relevant distinctions
and without conveying clarity (they spoke *amudros kai outhen
saphos*, *Metaph* I 4, 985 a 13).



By Aristotle's lights, all his predecessors engaged in their
causal investigation without a firm grasp of causality. They lacked a
complete understanding of the range of possible causes and their
systematic interrelations. Put differently, their *use* of
causality was not supported by an adequate *theory* of
causality. According to Aristotle, this explains why their
investigation, even when it resulted in important insights, was never
entirely successful.



This insistence on the doctrine of the four causes as an indispensable
tool for a successful investigation of the world around us explains
why Aristotle provides his reader with a general account of the four
causes. This account is found, in almost the same words, in
*Physics* II 3 and *Metaphysic*s V 2.


## 2. The Four Causes



In the *Posterior Analytics*, Aristotle places the following
crucial condition on proper knowledge: we think we have knowledge of a
thing only when we have grasped its cause (*APost*. I 2, 71 b
9-11. Cf. *APost*. II 11, 94 a 20). That proper knowledge
is knowledge of the cause is repeated in the *Physics*: we
think we do not have knowledge of a thing until we have grasped its
why, that is to say, its cause (*Phys*. II 3, 194 b
17-20). Since Aristotle obviously conceives of a causal
investigation as the search for an answer to a why-question, and a
why-question is a request for an explanation, it can be useful to
think of a cause as a certain type of explanation.



This last statement calls for a few words of elaboration. To be sure,
not all why-questions are requests for an explanation that identifies
a cause, let alone a cause in the particular sense envisioned by
Aristotle. Still, Aristotle is clearly committed to the view that
giving the relevant causes is necessary and sufficient for offering a
scientific explanation. His conception of a cause has both a
*metaphysical* and an *epistemological*  component. Part
of the challenge for us is to do justice to both components. Following
a recent suggestion, we may say that "causes are not ways in
which we explain things, except derivatively, in virtue of the fact
that they are ways in which some elements of the natural world explain
others." (Stein 2012a: 705)



In *Physics* II 3 and *Metaphysics* V 2, Aristotle
offers his general account of the four causes. This account is general
in the sense that it applies to everything that requires an
explanation, including artistic production and human action. Here
Aristotle recognizes four different explanatory roles that a thing can
play. As a result, there are four different (kinds of) causes :


* *The material cause* or that which is given in reply to the
question "What is it made out of?" What is singled out in
the answer need not be material objects such as bricks, stones, or
planks. By Aristotle's lights, A and B are the material cause of
the syllable BA.
* *The formal cause* or that which is given in reply to the
question ""What is it?". What is singled out in the answer
is the essence or the what-it-is-to-be something.
* *The efficient cause* or that which is given in reply to
the question: "Where does change (or motion) come from?".
What is singled out in the answer is the whence of change (or
motion).
* *The final cause* is that which is given in reply to the
question: "What is its good?". What is singled out in
the answer is that for the sake of which something is done or takes
place.



All the four (kinds of) causes may enter in a non-coincidental way in
the explanation of something. Consider the production of an artifact
like a bronze statue. The bronze enters in the explanation of the
production of the statue as *the material cause*. Note that the
bronze is not only the material out of which the statue is made but it
is also the subject of change, that is, the thing that undergoes the
change and results in a statue. The bronze is melted and poured in
order to acquire a new shape, the shape of the statue. This shape
enters in the explanation of the production of the statue as *the
formal cause*. However, an adequate explanation of the production
of a statue requires also a reference to *the efficient cause*
or the principle that produces the statue. For Aristotle, this
principle is the art of bronze-casting the statue (*Phys*. II
3, 195 a 6-8. Cf. *Metaph*. V 2, 1013 b 6-9).



This result is mildly surprising and requires a few words of
elaboration. There is no doubt that the art of bronze-casting resides
in an individual artisan who is responsible for the production of the
statue. According to Aristotle, however, all the artisan does in the
production of the statue is the manifestation of specific knowledge.
This knowledge, not the artisan who has mastered it, is the salient
explanatory factor that one should pick as the most accurate
specification of the efficient cause (*Phys*. II 3, 195 b
21-25). 



By picking the art, not the artisan, Aristotle is not just trying to
provide an explanation for the production of the statue which is not
dependent upon the desires, beliefs, and intentions of the individual
artisan; rather, he is trying to offer an entirely different type of
explanation-namely, an explanation that does not make a
reference (implicit or explicit) to desires, beliefs, and intentions.
More directly, the art of bronze-casting the statue enters in the
explanation as the efficient cause because it helps us to understand
what it takes to produce a statue; that is to say, what steps are
required to produce a statue starting from a piece of bronze.



The question for us is this: can an explanation of the kind outlined
above be given without reference to the final outcome of the
production, namely the statue? The answer is emphatically
"no". A model is made for producing the statue. A mold is
prepared for producing the statue. The bronze is melted and poured for
producing the statue. Both the prior and the subsequent stage are for
the sake of a certain end, the production of the statue. Clearly, the
statue enters in the explanation of each step of the artistic
production as *the final cause* or that for the sake of which
everything in the production process is done.



In thinking about the four causes, we have come to understand that
Aristotle offers a *teleological explanation* of the production
of a bronze statue; that is to say, an explanation that makes a
reference to the *telos* or end of the process. Moreover, a
teleological explanation of the type sketched above does not crucially
depend upon the application of psychological concepts such as desires,
beliefs, and intentions. This is important because artistic production
provides Aristotle with a teleological model for the study of natural
processes, whose explanation does not involve beliefs, desires,
intentions, or anything of this sort. Some have objected that
Aristotle explains natural process on the basis of an inappropriately
psychological teleological model; that is to say, a teleological model
that involves a purposive agent who is somehow sensitive to the end.
This objection can be met if the artistic model is understood in
non-psychological terms. In other words, Aristotle does not
psychologize nature because his study of the natural world is based on
a teleological model that is consciously free from psychological
factors. (For a philosophically-minded reflection on the role that
artistic production plays in developing an explanatory model for the
study of nature, see Broadie 1987, pp. 35-50.)



By insisting on the art of bronze-casting as the most accurate
efficient cause of the production of the statue, Aristotle does not
mean to preclude an appeal to the beliefs and desires of the
individual artisan. On the contrary, there are cases where the
individual realization of the art obviously enters in the explanation
of the bronze statue. For example, one may be interested in a
particular bronze statue because that statue is the great achievement
of an artisan who has not only mastered the art but has also applied
it with a distinctive style. In this case it is perfectly appropriate
to make reference to the beliefs and desires of the artisan. Aristotle
seems to make room for this case when he says that we should look
"for general causes of general things and for particular causes
of particular things" (*Phys*. II 3, 195 b 25-26).
Note, however, that the idiosyncrasies that may be important in
studying a particular bronze statue as the great achievement of an
individual artisan may be extraneous to a more central (and more
interesting, at least for Aristotle) case. To understand why let us
focus on the study of nature. When the student of nature is concerned
with the explanation of a natural phenomenon like the formation of
sharp teeth in the front and broad molars in the back of the mouth,
the student of nature is concerned with what is *typical* about
that phenomenon. In other words, the student of nature is expected to
provide an explanation of why certain animals *typically* have
a certain dental arrangement. We shall return to this example in due
course. For the time being, it is important to emphasize this
important feature of the explanatory project attempted by Aristotle; a
feature that we must keep in mind in trying to understand his theory
of causality. This theory has in fact been developed primarily (but
not exclusively) for the study of nature.



So far we have been looking at what Aristotle calls *intrinsic
causes*, where "intrinsic" is a translation of the
Greek *kath'hauton*. However, Aristotle contrasts these
(kinds of) causes with the coincidental ones, where
"coincidental" is a translation of the Greek *kata
sumbebekos*.



This distinction can be appreciated by reflecting on our example of
bronze-casting a statue. We have seen that the whence of motion is the
artisan insofar as this person has mastered the art of bronze-casting
a statue. By Aristotle's light, the art of bronze-casting
insofar as is present in the artisan is the most accurate description
of the efficient cause of the statue. This is also an *intrinsic
efficient cause* of the statue. However, the person who is
responsible for bronze-casting the statue may be described in many
other ways. For example, this person may be described as a woman, the
sister of *X*, or the daughter of *Y*. Aristotle makes
it very clear that these descriptions, important as they are, are not
relevant when it comes to giving the efficient cause of the statue
because they do not enter in an explanatory relationship with the
final outcome of the production process brings about, namely the
bronze statue. In other words, saying that the daughter of *X*
produced the bronze statue does not convey any information as to how
the statue has come into being. In other words, this description is
extrinsic to the production process. It just so happens, by
coincidence, that the artisan is the daughter of *X* or the
sister of *Y*.



The distinction between intrinsic and coincidental causes helps us
underscore that the Aristotelian causes are expected to have
*explanatory power*.


## 3. The Four Causes and the Study of Nature



In the *Physics*, Aristotle builds on his general account of
the four causes by developing explanatory principles that are specific
to the study of nature. Here Aristotle insists that all four causes
are involved in the explanation of natural phenomena. By his lights,
the job of "the student of nature is to bring the why-question
back to them all in the way appropriate to the science of
nature" (*Phys*. II 7, 198 a 21-23). The best way
to understand this methodological recommendation is the following: the
study of nature is concerned with natural bodies insofar as they are
subject to change, and the job of the student of nature is to provide
the explanation of their natural change. The factors that are involved
in the explanation of natural change turn out to be matter, form, that
which produces the change, and the end of this change. Note that
Aristotle does not say that all four explanatory factors are involved
in the explanation of each and every instance of natural change.
Rather, he says that an adequate explanation of natural change may
involve a reference to all of them.



Aristotle goes on by adding a specification on his doctrine of the
four causes: the form and the end often coincide, and they are
formally the same as that which produces the change (*Phys*. II
7, 198 a 23-26). This is one of the several times where
Aristotle offers the slogan "it takes a human being to generate
a human being" (for example, *Phys*. II 2, 194 b 13;
*Metaph*. VII 7, 1032 a 25; VII 8, 1033 b 32; IX 8, 1049 b 25;
XII 3, 1070 a 8; XIV 5, 1092 a 16). This slogan is designed to draw
attention to the following, fundamental fact: the generation of a
human being can be understood only in light of the end of the process;
that is to say, the fully developed human being. The question thus
arises as to what it takes for a human being to be fully developed.
Aristotle frames his answer in terms of the human form, maintaining
that a human form is fully realized at the end of the generative
process. This process does not end at birth but continues until the
human being reaches its acme. But this does not explain why it takes
*a human being* to generate a human being. Note, however, that
a fully developed human being is not only the final outcome of the
generative process; it is also what initiates the entire process. For
Aristotle, the ultimate moving principle responsible for the
generation of a human being is a fully developed living creature of
the same kind; that is, a human being who is formally the same as the
final result of the generative process. (A final clarification is in
order here: Aristotle is committed to a hylomorphic explanation of
animal generation. His considered view is that the father supplies the
form whereas the mother provides the relevant matter.) 



Thus, the student of nature is often left with three types of causes:
the formal/final cause, the efficient cause, and the material cause.
However, the view that there are in nature causes besides material and
efficient causes was controversial in antiquity. According to
Aristotle, most of his predecessors recognized only the material and
the efficient cause. This explains why Aristotle cannot be content
with saying that formal and final causes often coincide, but he also
has to defend his thesis against an opponent who denies that final
causality is a genuine mode of causality.


## 4. Final Causes Defended



*Physics* II 8 contains Aristotle's most general defense
of final causality. Here Aristotle establishes that explaining nature
requires final causality by discussing a difficulty that may be
advanced by an opponent who denies that there are final causes in
nature. Aristotle shows that an opponent who claims that material and
efficient causes alone suffice to explain natural change fails to
account for their characteristic regularity. Before considering how
the defense is attempted, it is important to clarify that this defense
does not perform the function of a proof. By showing that an approach
to the study of nature that ignores final causality cannot account for
a crucial aspect of nature, Aristotle does not thereby prove that
there are final causes in nature. Strictly speaking, the only way to
prove that nature exhibits final causality is to establish it on
independent grounds. But this is not what Aristotle does in
*Physics* II 8. Final causality is here introduced as the best
explanation for an aspect of nature which otherwise would remain
unexplained.



The difficulty that Aristotle discusses is introduced by considering
the way in which rain works. It rains because of material processes
which can be specified as follows: when the warm air that has been
drawn up is cooled off and becomes water, then this water comes down
as rain (*Phys*. II 8, 198 b 19-21). It may happen that
the corn in the field is nourished or the harvest is spoiled as a
result of the rain, but it does not rain for the sake of any good or
bad result. The good or bad result is just a coincidence
(*Phys*. II 8, 198 b 21-23). So, why cannot all natural
change work in the same way? For example, why cannot it be merely a
coincidence that the front teeth grow sharp and suitable for tearing
the food and the molars grow broad and useful for grinding the food
(*Phys*. II 8, 198 b 23-27)? When the teeth grow in just
this way, then the animal survives. When they do not, then the animal
dies. More directly, and more explicitly, the way the teeth grow is
not for the sake of the animal, and its survival or its death is just
a coincidence (*Phys*. II 8, 198 b 29-32).



Aristotle's reply is that the opponent is expected to explain
why the teeth *regularly* grow in the way they do: sharp teeth
in the front and broad molars in the back of the mouth. Moreover,
since this dental arrangement is suitable for biting and chewing the
food that the animal takes in, the opponent is expected to explain the
*regular* connection between the needs of the animal and the
formation of its teeth. Either there is a real causal connection
between the formation of the teeth and the needs of the animal, or
there is no real causal connection and it just so happens that the way
the teeth grow is good for the animal. In this second case it is just
a coincidence that the teeth grow in a way that it is good for the
animal. But this does not explain *the regularity* of the
connection. Where there is regularity there is also a call for an
explanation, and coincidence is no explanation at all. In other words,
to say that the teeth grow as they do by material necessity, and to
say that this is good for the animal by coincidence is to leave
unexplained the regular connection between the growth of the teeth and
the needs of the animal. Aristotle offers final causality as his
explanation for this regular connection: the teeth grow in the way
they do for biting and chewing food and this is good for the animal.
(See Code 1997: 127-134.)



One thing to be appreciated about Aristotle's reply is that the
final cause enters in the explanation of the formation of the parts of
an organism like an animal as something that is *good* either
for the existence or the flourishing of the animal. In the first case,
something is good for the animal because the animal cannot survive
without it; in the second case, something is good for the animal
because the animal is better off with it. This helps us to understand
why in introducing the concept of end (*telos*) that is
relevant to the study of natural processes Aristotle insists on its
goodness: "not everything that is last claims to be an end
(*telos*), but only that which is best" (*Phys*.
II 8, 194 a 32-33).



Once his defense of the use of final causes is firmly in place,
Aristotle can make a step further by focusing on the role that matter
plays in his explanatory project. Let us return to the example chosen
by Aristotle, the regular growth of sharp teeth in the front and broad
molars in the back of the mouth. What explanatory role is left for the
material processes involved in the natural process? Aristotle does not
seem to be able to specify what material processes are involved in the
growth of the teeth, but he is willing to recognize that certain
material processes have to take place for the teeth to grow in the
particular way they do. In other words, there is more to the formation
of the teeth than these material processes, but this formation does
not occur unless the relevant material processes take place. For
Aristotle, these material processes are that which is necessary to the
realization of a specific goal; that which is necessary on the
hypothesis that the end is to be obtained.



Hypothetical necessity is often equated to conditional necessity. But
this equation can be a first approximation at best. Stating the
conditions under which something is the case is not yet giving a
successful explanation. In other words, conditional necessity is a
wider, and indeed weaker, notion than hypothetical necessity (I refer
the reader to Stein 2016: 353-382 for a lucid reflection on this
point).



*Physics* II 9 is entirely devoted to the introduction of the
concept of *hypothetical necessity* and its relevance for the
explanatory ambition of Aristotle's science of nature. In this
chapter, matter is reconfigured as hypothetical necessity. By so doing
Aristotle acknowledges the explanatory relevance of the material
processes, while at the same time he emphasizes their dependency upon
a specific end.


## 5. The Explanatory Priority of Final Causes



In the *Physics*, Aristotle builds on his general account of
the four causes in order to provide the student of nature with the
explanatory resources indispensable for a successful investigation of
the natural world. However, the *Physics* does not provide
*all* the explanatory resources for *all* natural
investigations. Aristotle returns to the topic of causality in the
first book of the *Parts of Animals*. This is a relatively
independent and self-contained treatise entirely devoted to developing
the explanatory resources required for a successful study of animals
and animal life. Here Aristotle completes his theory of causality by
arguing for the explanatory priority of the final cause over the
efficient cause.



Significantly enough, there is no attempt to argue for the existence
of four fundamental modes of causality in the first book of the
*Parts of Animals*. Evidently, Aristotle expects his reader to
be already familiar with his general account of the four causes as
well as his defense of final causality. The problem that here concerns
Aristotle is presented in the following way: since both the final and
the efficient cause are involved in the explanation of natural
generation, we have to establish what is first and what is second
(*PA* 639 b 12-13). Aristotle argues that there is no
other way to explain natural generation than by reference to what lies
at the end of the process. This has explanatory priority over the
principle that is responsible for initiating the process of
generation. Aristotle relies on the analogy between artistic
production and natural generation, and the teleological model that he
has developed for the explanation of artistic production. Consider,
for example, house-building. There is no other way to explain how a
house is built, or is being built, than by reference to the final
result of the process, the house. More directly, the bricks and the
beams are put together in the particular way they are for the sake of
achieving a certain end: the production of the house. This is true
also in the case of natural generation. In this context
Aristotle' slogan is "generation is for the sake of
substance, not substance for the sake of generation"
(*PA* 640 a 18-19). This means that the proper way to
explain the generation of an organism like an animal, or the formation
of its parts, is by reference to the product that lies at the end of
the process; that is to say, a substance of a certain type.



From Aristotle we learn that Empedocles explained the articulation of
the human spine into vertebrae as the result of the twisting and
turning that takes place when the fetus is in the womb of the mother.
Aristotle finds this explanation unacceptable (*PA* 640 a
19-26). To begin with, the fetus must have the power to twist
and turn in the way it does, and Empedocles does not have an
explanation for this fact. Secondly, and more importantly, Empedocles
overlooks the fact that it takes *a human being* to generate a
human being. That is to say, the originating principle of the
generation is a fully developed human being which is formally the same
as the final outcome of the process of generation. It is only by
looking at the fully developed human being that we can understand why
our spine is articulated into vertebrae and why the vertebrae are
arranged in the particular way they are. This amounts to finding the
role that the spine has in the life of a fully developed human being.
Moreover, it is only by looking at the fully developed human being
that we can explain why the formation of the vertebrae takes place in
the particular way it does. (For further information about the
explanatory priority of the final over the efficient cause, see Code
1997: 127-143.)



Perhaps we are now in the position to understand how Aristotle argues
that there are four kinds of causes and at the same time says that
proper knowledge is knowledge of *the* cause or knowledge of
*the* why (*APost*. I 2, 71 b 10-12, II 11, 94 a
20; *Phys*. II 3, 194 b 17-20; *Metaph*. I 1, 981
a 28-30). Admittedly, at least at first sight, this is a bit
confusing. Confusion dissolves when we realize that Aristotle
recognizes the explanatory primacy of the final/formal cause over the
efficient and material cause. Of course this does not mean that the
other causes can be eliminated or reduced to the formal cause. Quite
the contrary: Aristotle is adamant that, for a full range of cases,
all four causes must be given in order to give an explanation. More
explicitly, for a full range of cases, an explanation which fails to
invoke all four causes is no explanation at all. At the same time,
however, the final/formal cause is the primary cause and knowledge of
this cause amounts to knowledge of the why.


## 6. The Explanation of a Lunar Eclipse



We have already seen that Aristotle is not committed to the view that
everything has all four kinds of causes, Rather, his view is that a
scientific explanation requires up to four kinds of causes. We may
illustrate this point with the help of an example. Consider, in
particular, the case of a lunar eclipse. In the *Metaphysics*,
Aristotle says that an eclipse of the moon does not have a final cause
(*Metaph.* VIII 4, 1044 b 12). He also says that, strictly
speaking, a lunar eclipse does not have matter. Rather, it has a cause
that plays a role *analogous* to matter. This second claim can
be inferred from what Aristotle says about the things that exist by
nature but are not substances. With respect to these things, Aristotle
says that they do not have matter but rather something that underlies
(*Metaph.* VIII 4, 1044 b 8-9). In the case of a lunar
eclipse, that which underlies is the subject affected by the eclipse,
that is, the moon. The moon is not strictly speaking the matter of the
eclipse but rather the subject that undergoes an eclipse when the
earth comes in the middle between the moon and the sun. Should we give
the earth as the efficient cause of a lunar eclipse? We have to be
careful here. By saying that the moon is a deprivation of light caused
by the earth, we distinguish this particular deprivation of light from
other kinds of deprivation of light. Still, by citing the earth as the
efficient cause of a lunar eclipse, we are not yet giving the most
precise description of the efficient cause. More directly, we are not
yet saying what the earth is doing to cause a lunar eclipse. A lunar
eclipse is a deprivation of light caused by the interposition of the
earth between the sun and the moon. By coming in the middle of the
moon and the sun the earth blocks the light and causes the moon to
suffer an eclipse. Hence, it is the interposition of the earth between
the sun and the moon is *the proximate* efficient cause of a
lunar eclipse. Citing the proximate efficient cause is also giving the
most accurate description, and indeed the full explanation, of a lunar
eclipse. (An insightful discussion of how Aristotle explains natural
phenomena such as a lunar eclipse and sleep can be found in Code 2015:
11-45).



This brief discussion of the explanation of an eclipse of the moon
brings us back to a point that was already made in connection with
Aristotle's explanation of the production of an artifact such as
a bronze statue. There too we are required to look for the most
accurate description of the efficient cause, which is to be identified
with the art of bronze-casting a statue rather than the artisan. It is
possible to build on both examples to conclude that Aristotle is
concerned not only with finding the relevant kinds of causes but also
with giving the most accurate description of those causes. By his
lights, it is only the most accurate description of all the relevant
causes that gives us the full explanation, and thereby scientific
knowledge, of something.


## 7. Conclusion



The study of nature was a search for answers to why-questions before
and independently of Aristotle. A critical examination of the language
of causality used by his predecessors, together with a careful study
of natural phenomena, led Aristotle to elaborate a *theory* of
causality. This theory is presented in its most general form in
*Physics* II 3 and in *Metaphysics* V 2. In both texts,
Aristotle argues that a final, formal, efficient or material cause can
be given in answer to a why-question.



Aristotle further elaborates on the topic of causality in the rest of
*Physics* II and in *Parts of Animals* I. Aristotle
explores the systematic interrelations among the four modes of
causality and argues for the explanatory priority of the final cause.
In so doing Aristotle not only expands on his theory of causality; he
also builds explanatory principles that are specific to the study of
nature. Aristotle considers these principles an indispensable
theoretical framework for a successful investigation of the natural
world. Both *Physics* II and *Parts of Animals* I have a
foundational character. More directly, Aristotle expects the student
of nature to have mastered the principles advanced in these two texts
before engaging in the investigation of the natural world.



Although Aristotle's theory of causality is developed in the
context of his science of nature, its application goes well beyond the
boundaries of natural science. This is already clear from the most
general presentation of the theory in *Physics* II 3 and in
*Metaphysics* V 2. Here the four causes are used to explain
human action as well as artistic production. In addition, any
theoretical investigation that there might be besides natural science
will employ the doctrine of the four causes. 



Consider, briefly, the case of Aristotle's *Metaphysics*.
Here Aristotle is seeking wisdom. Part of the argument of the
*Metaphysics* is in an attempt to clarify what sort of wisdom
Aristotle is seeking. Suffice it to say that Aristotle conceives of
this wisdom as a science of substance that is, or is a part of, a
science of being qua being (for further information about this
argument, see the entry Aristotle's Metaphysics, especially
Sections 1 and 3.) What is important is that this science consists in
a causal investigation, that is, a search for the relevant causes.
This helps us to understand why the most general presentation of
Aristotle's theory of causality is repeated, in almost the same
words, in *Physics* II 3 and in *Metaphysics* V 2.
Although the *Physics* and the *Metaphysics* belong to
two different theoretical enterprises, in both cases we are expected
to embark on an investigation that will eventuate in causal knowledge,
and this is not possible without a firm grasp of the interrelations
between the four (types of) causes.


## 8. Glossary of Aristotelian Terminology


* account: *logos*
* art: *techne*
* artisan: *technites*, *demiourgos*
* cause: *aitia*, *aition*
* difficulty: *aporia*
* end: *telos*
* essence: *to ti en einai*
* form: *eidos*
* generation: *genesis*
* goal: *telos*
* knowledge: *episteme*
* hypothesis: *hypothesis*
* necessity: *ananke*
* principle: *arche*
* substance:*ousia*
* why: *dia ti, dioti*
* wisdom: *sophia*