In this paper I explore Aristotle’s views on natural kinds and the compatibility of pluralism and realism, a topic that has generated considerable interest among contemporary philosophers. I argue that, when it came to zoology, Aristotle denied that there is only one way of organizing the diversity of the living world into natural kinds that will yield a single, unified system of classification. Instead, living things can be grouped and regrouped into various cross-cutting kinds on the basis of objective similarities (...) and differences in ways that subserve the explanatory context. Since the explanatory aims of zoology are diverse and variegated, the kinds it recognizes must be equally diverse and variegated. At the same time, there are certain constraints on which kinds can be selected. And those constraints derive more from the causal structure of the world than from the proclivities of the classifier (hence the realism). This distinguishes Aristotle’s version of pluralistic realism from those contemporary versions (like Dupré’s “promiscuous realism”) that treat all or most classifications of a given domain as equally legitimate and not just a sub-set of kinds recognized by the science that studies it. By contrast, Aristotle privileges scientifically important kinds on the basis of their role in causal investigations. On this picture natural kinds are those kinds with the sort of causal structure that allows them to enter into scientific explanations. In the final section I argue that Aristotle’s zoology should remain of interest to philosophers and biologists alike insofar as it combines a pluralistic form of realism with a rank-free approach to classification. (shrink)

I endeavour in this article to present Ibn Taymiyya's theory of nominal definition as an alternative to logical definition. Ibn Taymiyya argues that nominal definition is based on concrete principles that are subject to experiment. Furthermore, the function of definition is akin to the 'name' because it aims at distinguishing any one object from others but not at reaching the entity of things. Nominal definition aims to define the name or the named, and this aim can be achieved by translation (...) or by interpretation. Translation is the movement from one name to another or from one named object to another. Interpretation is movement from a name to a named object or from a named object to a name. (shrink)

This dissertation explores Aristotle’s use of teleology as a principle of explanation, especially as it is used in the natural treatises. Its main purposes are, first, to determine the function, structure, and explanatory power of teleological explanations in four of Aristotle’s natural treatises, that is, in Physica (book II), De Anima, De Partibus Animalium (including the practice in books II-IV), and De Caelo (book II). Its second purpose is to confront these findings about Aristotle’s practice in the natural treatises with (...) the theoretical picture of the structure of teleological explanations gained from Aristotle’s theory of scientific demonstration. For this purpose a new interpretation of Analytica Posteriora II.11 is presented. This study thereby contributes to recent scholarship on the relation between Aristotle’s philosophy of science and his philosophy of nature, while at the same time adding to our knowledge of Aristotle’s notion of teleology in terms of its explanatory merits and limits. (shrink)

According to Aristotle, definition is the first step to aquire scientific knowledge. And the full knowledge of objects is possible only by knowing their essence and essential definition. Following Aristotle, Avicenna thinks that the full knowledge of things is gained through the knowledge of their essence. Admitting the difficulty of understanding the essentials of objects, he states, based on his essentialist doctrine, that real definition should imply quiddity, truth and perfection of essential existence of the limited object so that it (...) represents all its essence. But man can not identify essentials of objects and true definitions of them. Avicenna describes details of all kinds of definitions, and this article we modifies and completes the rules of Aristotle’s theory of definition. In will explain it. Keywords: Essentialism, Real Definitions, Genus and Differentia, Aristotle, Avicenna. 1. Introduction Distinguishing between essential and accidental attributes of objects, Aristotle chooses essentialism as his approach. Avicenna shows interest in Aristotelian essentialism in some of his works, but in other works he claims that kowing the essential features of objects is beyond human epistemic capacity and thus modifies the rules of the Aristotelian definitions. 2. Aristotelian Essentialism about Definition: According to Aristotle, sensitive perception represents the knowledge of particular objects and is not considered an example of scientific knowledge; but these very sensitive observations assist the intellect to discover the hidden universals within particular objects and pave the way for the reason to get access to the specific form of objects and distinguish between their essential and accidental features and succeed in revealing their true nature. Aristotle in his metaphysical discussions distinguishes between real and nominal definitions and declares both of them possible and considers the real definition to be the first step for acquiring the scientific knowledge of objects. According to Aristotle, perfect knowledge of objects can be achieved merely by the knowledge of their nature and essence. Real definition of an object is a statement that expresses its essential features, without mentioning the name of the object itself in the definition. This definition is composed of genus and differentia, and it is always universal and affirmative. 3. Avicenna’s Notion of Definition and His Critisism of Aristotelian Definition: Avicenna’s words in Shifa and Isharat, like followers of Aristotle, are focused on the possibility of the knowledge of essential features of objects; in the essay devoted to the issue of definition in his book entitled Nijat, Avicenna endorses the possibility of definition and at the same time highlights the absolute difficulty of definition, including real and nominal definitions. However, in his book entitled Ta’liqat he clearly argues that true definition of objects is out of the reach of man. In his book entitled Mantiq al-Mashriqyyin, he provides a detailed discussion of various types of definition and makes some modifications in Aristotelian rules of definition. In Ta’liqat, Avicenna declares real definition composed of genus and differentia to be impossible and criticizes Aristotle’s method as incorrect. He restricts human knowledge of objects to knowing their features, requirements and accidents and denied the possibility of knowing their essential features and real definitions. He claims that the first epistemic means of human being is sense, which touches the superficial aspects of objects; then man distinguishes between identical and different perceptions using his intellectual powers and reason and thus understands some of their attributes and requirements and remains uninformed about others. If man was able to perceive the truth of objects he could be aware of all requirements; then man is not able to know the essence and truth of objects. Moreover, difference of opinions regarding the nature of objects is a sign of human reason’s inability to understand essential attributes of objects. Knowledge of the true differentia of compound objects lies beyond the ability of man’s intellectual perception and he has access only to their requirements. So, man calls their common requirements as genus while he calls their special requirements differentia and particular accident. For example, thinking is not the true differentia of human being, but rather one of the requirements of his true differentia. Furthermore, simple objects have no genus and differentia so that man could know them by knowing these. For this reason, man does not have any access to the knowledge of the essence of objects. The completely immaterial objects are considered as externally simple and intellectually compound, as accidents. The essence of the completely immaterial entities is simple and lacks any matter or external form. We assume genus and differenia for them and bring these in their essential definition. Genus and differentia are declared to be mental matter and form when these are considered without any condition and in this case, they are parts of real definition, not components of simple entities. So, in fact, neither the essence of compound entities nor the essence of simple entities is accessible to man. 4. Conclusion: Aristotle believes that every object has an essence and definition aims at knowing this very essence. Aristotle’s followers contend that true definition is difficult to reach, but many Muslim philosophers in general and Avicenna in particular in some of his works argue that essential attributes of objects lie beyond the limits of human intellect. Reaching the true genus and differentia of objects and knowing their essential features is not possible for man. What is declared to be the differentia of the object is in fact its logical differentia, which is in turn the requirement of true differentia. However, knowledge of some of the essential features and requirements leads to the undetailed knowledge of the truths of objects and their features. The major purpose of the definition is thus achieved and man is delivered from the vortex of doubt and sophistry. References: - Aristotle, Aristotelian logic, Abdul Rahman Badawi’s research, Beirut, Dar al-Qalam, 2,418 - Aristotle, metaphysics, translated by Mohammad Hassan Lotfi, Tehran, Tarh-e-now, 63 - Ibn Sina, Hussein bin Abdullah, Mantiq Al-Mashriqiyin, Shukri al-Najjar’s introduction, Beirut, Dar Al-hedatheh, 59-67 - Ibn Sina, Al-ta’liqat, Abdul Rahman Badawi’s research, Qom, School Al-Alam al-salami, 34. (shrink)