Arabic Philosophy, Lecture 6: Al-Fârâbî on Logic and the Sciences

Instructor: Dr Peter Adamson (

The Context of al-Fârâbî’s Thought: Logic and Grammar

• The Peripatetic movement in Baghdad: Farabi is following the lead of Abû Bishr Mattâ and his teacher, another Christian, Yuhannâ b. Haylân, with whom he read as far as the Posterior Analytics.

• The interest of these figures in Logic is their most striking intellectual commitment; it also figures in a celebrated controversy between Abû Bishr and Abû Sa’îd al-Sîrâfî.

• The basic position taken by al-Sîrâfî is that there is no such thing as a "universal" logic that is the standard of correctness; rather correctness of speech is proper to the language used, and no meaning can be expressed except in a specific language.

• Farabi’s position is precisely the opposite: "logic is associated in some way with grammar insofar as it establishes verbal rules. But it is distinguished from it because grammar establishes rules for the language of a certain nation, whereas logic establishes the rules common to all languages."

The Philosophical Curriculum

• Farabi inherits an Aristotelian curriculum from the Alexandrian tradition, in which (among other things) we have a hierarchical classification, the inclusion of rhetoric and poetry under logic, a division between practical and theoretical sciences.

• The logical structure of the sciences: principles of instruction vs. principles of being. (See the reading for today’s lecture.)

• The problem of the subject of metaphysics.

• Attitude towards kalâm and religion.

Classifications of the sciences

• In addition to this normative curriculum, Farabi has a historical account of the actual development of the sciences, which is set out most fully in his Kitâb al-hurûf.

• This may also be compared to his treatment of Plato’s and Aristotle’s writings: he knows Aristotle much better than Plato, of course.

Arabic Philosophy, Lecture 6: Al-Fârâbî on Logic and the Sciences

Reading: Al-Fârâbî, Attainment of Happiness, sections 4-5 (Mahdi trans.)

So let it be clear to you that before setting out to investigate problems we must realize that all these methods have to be learned as an art: we must know how to distinguish the various methods by means of specific differences and marks designating each, and we must have our innate and natural aptitude for science developed through an art that can provide us with knowledge of these differences, since our innate capacity alone is insufficient for differentiating these methods from each other. This means that we must ascertain (1) the conditions and states of the first premises and the order of their arrangement, if they are to lead the investigator necessarily to the truth itself and to certainty about it; (2) the conditions and states of the first premises and the order of their arrangement when they cause the investigator to wander from the truth, perplex him, and prevent him from perceiving even where the truth of his problem might lie; (3) the conditions and states of the first premises and the order of their arrangement when they provide belief and persuasion about a problem and make one even fancy that this is certainty, although it is not; and (4) the conditions and states of the first premises and the order of their arrangement when they lead the investigator not to the truth itself but to a similitude and image of the truth. Only after knowing all of this should we set out to seek knowledge of the beings by investigating them ourselves or being instructed by others. For it is only by knowing everything we have mentioned that we find out how to investigate and how to instruct and study. This faculty enables us to discern whether what we infer is certain knowledge or mere belief, whether it is the thing itself or its image and similitude. It enables us also to examine what we have learned from others and what we ourselves teach others.

The primary cognitions relative to every genus of beings are the principles of instruction in that genus, provided they possess the states and conditions through which the student is led to the certain truth about what he seeks to know in the genus. If all or most of the species comprised by the genus should possess causes by which, from which or for which these species exist, then these are the principles of being of the species comprised by the genus, and one should attempt to know them. Now when the primary cognitions relative to some genus are identical with the causes of the species comprised by that genus, then the principles of instruction in it are identical with the principles of being. Demonstrations proceeding from these primary cognitions are called demonstrations of why the thing is, for in addition to knowledge of whether the things is, they give an account of why it is. But when the cognitions possessing the states and conditions [that lead to the certain truth about what we seek to know] in a genus of beings are the grounds of our knowledge that the species comprised by that genus exist, without being the grounds of the existence of any of them, then the principles of instruction in that genus are different from the principles of being. The demonstrations proceeding from these cognitions will be demonstrations of whether the thing is and demonstrations that it is, not demonstrations of why it is.

Arabic Philosophy, Lecture 7: Al-Fârâbî’s Metaphysics and Cosmology

Instructor: Dr Peter Adamson (

• Farabi’s fidelity to Aristotle: Druart’s thesis and division of his works into the Aristotelian, programmatic, and emanationist. (Perhaps fails to take sufficient account of the Alexandrian inspiration of Farabi’s program.)


• The heavenly bodies: nine spheres, each with a soul and an intellect.

• The role of the Active Intellect: is it a "giver of forms (dator formarum)"? Or does celestial motion do the work? Its role in human intellection (see further next lecture).

• The sublunar world: form and matter. Soul is distinct from and superior to form.

God (the First Cause)

• Farabi simply declares at the outset of Opinions that there is an uncaused First Cause, and "one ought to believe that it is God." Other things get their existence (wujûd) from it, but it does not get its existence from anything else.

• Farabi does call the First Cause necessary but does not explicitly deploy a distinction between essence and existence, nor does he prove that there is a Necessary Existent.

• God’s knowledge: God is an intellect and knows all things by knowing Himself.

• The names of God: it must be given the most perfect names, which must not be taken to imply multiplicity in the essence. No relations allowed.

• The emanation of the intellects: this does not perfect God, nor does He have an end in creating. In what sense is this "emanation"?

• Generation of matter by the celestial bodies.

• The merely "possible" beings and Farabi’s understanding of modality.

Arabic Philosophy, Lecture 7: Al-Fârâbî’s Metaphysics and Cosmology

The Political Regime: the simplicity of God, and God as intellect

The First Cause is indivisible in its essence by definition. I mean, it is not divisible into things by which it is constituted as substance. For it is impossible that each part of the definition that would explain its essence would indicate a part of that by which it is constituted as substance. For if this were so, the parts by which it would be constituted as substance would be the causes of its existence, the way that the concepts indicated by the parts of the definition are causes of the existence of that which subsists by them. But that is impossible for it, because it is a "First". So if it is not divisible in this way, still less would it be divisible according to quantity and the other kinds of divisibility. So it is also one in this other way.

Therefore it is also impossible that its existence, by which it is set apart from all other existents, should be other than that existence by which it is existing by itself. Therefore its being set apart from everything else is due to a oneness which is its essence. For one of the meanings of "oneness" is the peculiar existence by which each being is distinct from everything else. And it is because of this oneness that each being is said to be "one" in the sense that it exists with the existence that is peculiar to it; and this one of its meanings is conformed to the existent. So the First is also one in this respect and more entitled than anything else to the name of the one and its meaning.

And because it has no matter in any way, it is by its substance intellect. For what prevents something from being intellect and from intellecting in act is matter. It is also intellected from the standpoint of its being intellect, since what is intellect in it is intellected by that which in it is intellect. It has no need, for being intellected, of some other essence outside of it which would intellect it, but it itself intellects its own essence and so it becomes, by what it intellects of its essence, intellecting, and by the fact that its essence intellects it, it becomes intellected. Likewise it does not need, for being intellect and intellecting, another essence or something else that it would acquire from outside; but it is intellect and intellecting by its intellecting its essence. For the essence that intellects is that which is intellected.

Arabic Philosophy, Lecture 8: Al-Fârâbî’s Epistemology

Instructor: Dr Peter Adamson (

The background to the theory of Risâla fî ’l-‘Aql

• Aristotle and the scientific requirement for universal knowledge: Posterior Analytics II.19 is his attempt to explain how we achieve such knowledge.

• The psychological mechanism for intellectual knowledge is explained in the De Anima: here Aristotle distinguishes between potential and active intellect.

• Lingering problems: how do we go from sense experience, which is always of the particular, to intellection, which is always of the universal? How does the intellect that grasps these universals relate to the body?

• Debates amongst the commentators: Alexander identifies active intellect with god, whereas for Themistius we each have our "own" active intellect (this is what "does the thinking", and my intellect is "what it is to be me" — my essence).

• It has recently been suggested (Geoffrey) that Farabi knew only Alexander, and not the De Anima itself. But there are historical implausibilities here.

Potential intellect

"The intellect in potentiality is some soul, or part of a soul, or one of the faculties of the soul, or something whose essence is ready and prepared to abstract the quiddities of all existing things and their forms from their matters, so that it makes all of them a form for itself or forms for itself."

• This commitment to abstraction sets Farabi apart from Kindi. Farabi illustrates what he has in mind with the example of a stamp on wax, which is borrowed ultimately from the De Anima, where it is used to explain the relation between soul and body.

"In accordance with this example you must imagine the coming to be of the forms of existing things in that essence which Aristotle in the De Anima calls intellect in potentiality… when there come to be in it the forms of existing things, in accordance with the example which we have mentioned, then that essence becomes intellect in actuality."

• Notice that the potential intellect is intrinsically merely potential; as soon as we have actual thinking going on, we are talking about actual intellect. This suggests that the "potential intellect" is merely a capacity.

Actual intellect

"Before they were abstracted from their matters [the intelligibles] were intelligibles in potentiality, but when they were abstracted, they became intelligibles in actuality, because they became forms for that essence [sc. the intellect. But that they are intelligibles in actuality and that the intellect is an intellect in actuality is the very same thing."

• The idea of merely potential intelligibles takes us back to the central difficulty of how abstraction allows for universality (they must be stripped of their accidental categorial features, e.g. place, time, quality, action). Note here too Farabi’s claim that the intellect and its intelligibles are one and the same.

• Then the actual intellect becomes something in its own right, and is able to think about itself: "when the intellect in actuality thinks the intelligibles that are forms in it, insofar as they are intelligibles in actuality, then the intellect of which it was first said that it is the intellect in actuality, becomes now the acquired intellect."

Acquired intellect

• This further stage thus involves reflexivity; this is one of Farabi’s subtler and more philosophically interesting claims in On Intellect.

"The forms can only be perfectly thought after all intelligibles or most of them have become thought in actuality, and the acquired intellect has come into being. The acquired intellect is like a form for the intellect which is in actuality, and the intellect in actuality is like a substrate and matter for the acquired intellect."

• Thus acquired intellect is the highest attainment of an individual human intellect: it is all (or almost all) the universals arranged via self-reflexion in a scientific order.

• However, this order is only the order of things as we come to understand them. The intelligibles themselves are ordered "properly" only in the agent intellect.

Agent intellect

"The agent intellect is a separated form which never existed in matter nor will ever exist in it, and it is in a certain manner an intellect in actuality close in likeness to the acquired intellect. It is that principle which makes that essence which was an intellect in potentiality, an intellect in actuality, and which makes the intelligibles which are intelligibles in potentiality, intelligibles in actuality."

• Active intellect is thus needed to facilitate the acquisition of universals by individual intellects: thus it is compared to light’s role in vision (following Alexander’s reading of De Anima III.5).

• The active intellect is not unlike a Neoplatonic nous: in it the forms are "indivisible" and its essence bestows likenesses of the forms upon matter. Thus active intellect plays an ontological, as well as an epistemological, role.

• Why does the active intellect produce bodies only intermittently? (This question goes back to Aristotle’s critique of Plato’s theory of Forms.) Because the matter needs to be prepared to receive it:

"The defect does not come from its essence, but either from the fact that the agent intellect does not always encounter something in which it can act, because there does not exist prepared the matter and the substratum in which it can act, or from the fact that it has an impediment outside of it, so that it cease, or from both of these things together."

• Meanwhile it is the heavens that are the cause of matter.

• What is the connection between the epistemic and ontological functions of the agent intellect?

[All translations by Hyman, from Hyman and Walsh.]

Arabic Philosophy, Lecture 9: Al-Fârâbî’s Political Thought

Instructor: Dr Peter Adamson (

The context

• Al-Farabi’s main sources for ethical and political thought are, respectively, Aristotle’s Ethics and Plato’s Republic. An insufficiently appreciated point here is that he must therefore bring together two incompatible systems of practical thought.

• This comes out most strongly in the Aphorisms of the Statesman (or Selected Aphorisms), which closely follows the Ethics and then switches to the Republic (at about section 57, significantly, after a discussion of the intellectual virtues).

The structure of practical philosophy

• Recall that practical philosophy is opposed by al-Farabi to theoretical philosophy, and is said to differ from it by having to do with "the voluntary". Thus practical philosophy is necessary because of our capacity for free choice.

• Practical issues arise at the level of the individual and the state: ethics and politics. Al-Farabi’s ethical teaching is much like Aristotle’s: he affirms that virtue lies in choosing the mean, for instance. But in most of his works that deal with politics (e.g. the two systematic books, the Book of Religion) he skips ethics and goes straight to politics.

The pursuit of happiness

• This seems to be because the vast majority of people will not be capable of attaining virtue, and thus happiness, which he at least sometimes identifies as residing in the afterlife.

• We get a division of society into classes, which is clearly based on the Republic.

• At the top is the ideal ruler or king, who exercises the kingly craft. The king is a philosopher who is able to persuade the people to pursue happiness and virtue, in the way appropriate for their class.

• Thus al-Farabi stresses the need for the king to grasp theoretical philosophy and practical philosophy as a universal science. However he also needs to apply this to specific circumstances: the analogy to medicine at Book of Religion 14c.

• Al-Farabi is very interested in what happens when there is no ideal ruler: the various strategies for coping with this (fiqh as a last resort), and the bad cities.

• Sometimes al-Farabi also says that this king would possess a "revelation" that helps him communicate truths to the masses. This takes us to the problem of religion.


• In the Book of Religion (K. al-Milla) and elsewhere al-Farabi presents religious opinions (note the term used here) as a persuasive or rhetorical version of the truths grasped in philosophy. See text on reverse of sheet.

Excerpt from al-Farabi, The Book of Religion (4-6)

The first type of opinions specified in religion is twofold: an opinion designated by its proper name, which customarily signifies it itself; or an opinion designated by the name of what is similar to it. Thus the determined opinions in the virtuous religion are either the truth or a likeness of the truth. In general, truth is what a human being ascertains, either by himself by means of primary knowledge, or by demonstration. Now any religion in which the first type of opinions does not comprise what a human being can ascertain either in itself (bi-nafsihi) or by demonstration and in which there is no likeness of anything he can ascertain in one of these two ways is an errant religion.

Thus, virtuous religion is similar to philosophy. Just as philosophy is partly theoretical and partly practical, so it is with religion: the calculative theoretical part is what a human being is not able to do when he knows it, whereas the practical part is what a human being is able to do when he knows it. The practical things in religion are those whose universals are in practical philosophy. That is because the practical things in religion are those universals made determinate by stipulations restricting them, and what is restricted is more particular than what is unqualified, e.g. saying "the human being who is writing" is more particular than saying "the human being." Therefore all virtuous laws are subordinate to the univerals of practical philosophy. The theoretical opinions that are in religion have their demonstrative proofs in theoretical philosophy and are taken in religion without demonstrative proofs.

Therefore, the two parts of which religion consists are subordinate to philosophy. For something is said to be a part of a science or to be subordinate to a science in one of two ways: either the demonstrative proofs of what is assumed in it without demonstrative proofs occur in that science, or the science comprising the universals is the one that gives the reasons for the particulars subordinate to it. The practical part of philosophy is, then, the one that gives the reasons for the stipulations by which actions are made determinate… Further, if to know something is to know it demonstratively, then this part of philosophy is the one that gives the demonstrative proof for the determined actions that are in virtuous religion…

Dialectic yields strong presumption about all or most of what demonstrative proofs yield certainty about, and rhetoric persuades about most of what is not such as to be proven by demonstration or looked into by dialectic. Moreover, virtuous religion is not only for philosophers or only for someone of such a station as to understand what is spoken about only in a philosophical manner. Rather most people who are taught the opinions of religion and instructed in them and brought to accepts its actions are not of such a station, and that is either due to nature or because they are occupied with other things. Yet they are not people who fail to understand generally accepted or persuasive things. For that reason, both dialectic and rhetoric and of major value for verifying the opinions of religion for the citizens and for defending, supporting and establishing those opinions in their souls, as well as for defending those opinions when someone appears who desires to deceive the followers of the religion by means of argument, lead them into error, and contend against the religion. [Butterworth translation]