For more on Aristotle’s virtue-based ethics, see the entry on .

In the Physics, Aristotle builds on his general account of thefour causes by developing explanatory principles that are specific tothe study of nature. Here Aristotle insists that all four causes areinvolved in the explanation of natural phenomena, and that the job of“the student of nature is to bring the why-question back to themall in the way appropriate to the science of nature”(Phys. 198 a 21–23). The best way to understand thismethodological recommendation is the following: the science of natureis concerned with natural bodies insofar as they are subject tochange, and the job of the student of nature is to provide theexplanation of their natural change. The factors that are involved inthe explanation of natural change turn out to be matter, form, thatwhich produces the change, and the end of this change. Note thatAristotle does not say that all four explanatory factors are involvedin the explanation of each and every instance of naturalchange. Rather, he says that an adequate explanation of natural changemay involve a reference to all of them. Aristotle goes on by adding aspecification on his doctrine of the four causes: the form and the endoften coincide, and they are formally the same as that which producesthe change (Phys. 198 a 23–26). This is one of the severaltimes where Aristotle offers the slogan “it takes a man togenerate a man” (for example, Phys. 194 b 13;Metaph. 1032 a 25, 1033 b 32, 1049 b 25, 1070 a 8, 1092 a16). This slogan is designed to point at the fundamental fact that thegeneration of a man can be understood only in the light of the end ofthe process; that is to say, the fully developed man. What a fullydeveloped man is is specified in terms of the form of a man, and thisform is realized in its full development at the end of thegeneration. But this does not explain why it takes a man togenerate a man. Note, however, that a fully developed man is not onlythe end of generation; it is also what initiates the entireprocess. For Aristotle, the ultimate moving principle responsible forthe generation of a man is a fully developed living creature of thesame kind; that is, a man who is formally the same as the end ofgeneration.

This is actually the form of metaphysics.

For a fuller account of Aristotle’s achievements in logic, see the entry on .

Aristotle: Metaphysics | Internet Encyclopedia of Philosophy

Aristotle’s writings tend to present formidable difficulties tohis novice readers. To begin, he makes heavy use of unexplainedtechnical terminology, and his sentence structure can at times provefrustrating. Further, on occasion a chapter or even a fulltreatise coming down to us under his name appears haphazardlyorganized, if organized at all; indeed, in several cases, scholarsdispute whether a continuous treatise currently arranged under a singletitle was ever intended by Aristotle to be published in its presentform or was rather stitched together by some later editor employingwhatever principles of organization he deemed suitable.[] This helps explain whystudents who turn to Aristotle after first being introduced to thesupple and mellifluous prose on display in Plato’s dialoguesoften find the experience frustrating. Aristotle’s proserequires some acclimatization.

Aristotle on the existence of God - The Logic Museum

After thirteen years in Athens, Aristotle once again found cause toretire from the city, in 323. Probably his departure wasoccasioned by a resurgence of the always-simmering anti-Macedoniansentiment in Athens, which was free to come to the boil after Alexandersuccumbed to disease in Babylon during that same year. Because ofhis connections to Macedon, Aristotle reasonably feared for his safetyand left Athens, remarking, as an oft-repeated ancient tale would tellit, that he saw no reason to permit Athens to sin twice againstphilosophy. He withdrew directly to Chalcis, on Euboea, an islandoff the Attic coast, and died there of natural causes the followingyear, in 322.[]

Statue of Aristotle (1915) by Cipri Adolf Bermann at the University of Freiburg im Breisgau
The Standard English Translation of Aristotle’s Complete Worksinto English is:

SparkNotes: Aristotle: Metaphysics

So, unfortunately, the bottom line on pleasure may still be Aristotle:

Men erring on the side of deficiency as regards pleasures (), and taking less than a proper amount of enjoyment (, "enjoying") in them, scarcely occur; such insensibility () is not human () [, Book III, xi, 7, Loeb Classical Library, Harvard U.

The best set of English translations with commentaries is theClarendon Aristotle Series:

Aristotle | Internet Encyclopedia of Philosophy

Aristotle’s attitude towards explanation is best understoodfirst by considering a simple example he proposes in Physicsii 3. A bronze statue admits of various different dimensions ofexplanation. If we were to confront a statue without firstrecognizing what it was, we would, thinks Aristotle, spontaneously aska series of questions about it. We would wish to know what itis, what it is made of, what brought it about,andwhat it is for. In Aristotle’s terms, inasking these questions we are seeking knowledge of the statue’sfour causes (aitia): the formal, material, efficient,and final. According to Aristotle, when we haveidentified these four causes, we have satisfied a reasonable demand forexplanatory adequacy.

This scandalized Aristotelians, since allowing the equal  of contradictions destroys just about the most basic principle of .

Thomas Aquinas: Commentary on Aristotle's Metaphysics…

denied the first, by taking the equivalent of Kant's Transcendental Deduction as itself a part of metaphysics and a proof, by means of novel principles of "dialectical" logic, of moral and metaphysical truths.