Summary of Preface to Metaphysics

The following summary of Jacques Maritain’s Preface to Metaphysics – Seven Lectures on Being (full text), with some quotes from a couple other books, is not a scholarly work, so there will be no quotation marks or italics apart from those already in the text. Passages between brackets are my comments or paraphrases.

Being As Such
The object of metaphysics is the knowledge of being as such. Being is the first object attained by every man the instant he begins to think as a rational creature, but at this stage it is a more or less confused perception of the concrete being, enveloped or embodied in sensible things. The metaphysician will consider the essence, or nature, of sensible things by abstracting, or disengaging their intelligible values from particularized objects.

The first operation of the mind is thus to apprehend essences (what is universal, what is the nature of the thing), but the term of knowledge is the actual, existing being, the esse in the strict sense. Thomist philosophy does not stop short at essences. It is to existence itself that the intellect proceeds when it formulates within itself a judgment by composition and division (second operation of the mind) corresponding to what a thing is or is not outside the mind.

Intuition of Being
The being which is the subject matter of metaphysics, being as such, is really the common being hidden under this most commonplace of words is, but as in Edgar Poe’s tale of the Purloined Letter, we do not see immediately for what it is the thing just before our eyes. It is the most ordinary object of common knowledge that the metaphysician uncovers through the intuition of being and draws out of its ironical commonplace.

The being of the metaphysician is not to be confused with the vague being of common sense, or the particularised being of the natural sciences, or the being divested of reality of genuine logic, or yet the pseudo-being of false logic. It is real being in all the purity and fullness of its distinctive intelligibility – and mystery.

Transcendentals and Analogy of Being
The intuition of being is also the intuition of its transcendental character and analogical value.

In Aristotelian logic, being is considered through its predicaments (categories), but before thinking of, for example, Peter as a man, that is, before predicating anything about this particular being, I think of him as an existing being. Being is not the privilege of any class or species, it transcends everything else; it is a transcendental. Being is everywhere, at the same time one and multiple. All beings have being in common, thus it is one (but not at all like Hegel’s monism), and they have it following each its essence or nature, thus it is also various (but not at all like Cartesian pluralism).

Analogy of Being
Being as such, the distinctive object of the metaphysician, is grasped by a pure and genuine intuition only when its polyvalence or analogy, its essentially analogous value, is grasped at the same time.

This analogical character, called the “analogy of strict proportionality,” is inscribed in the very nature of the concept of being. It is analogous from the outset, not a univocal concept afterwards employed analogously. It is essentially analogous, polyvalent, but in itself it is a simple unity of proportionality, that is, it is purely and simply manifold while being one in a particular respect.

The reality which I attain in the notion of being, in the intuition of being, is richer and more pregnant with intelligible values than the idea of being by itself immediately reveals. By an intrinsic necessity it must in a sense overflow the very idea in which it is objectified. Metaphysicians recognise a certain number of universal modes of being, as universal as being itself, which are termed transcendentals (passiones entis, passions of being). For example unity is being in as much as it is undivided. Truth is being in as much as it confronts intellection, thought. An object is true, or conforms to what it thus says itself to thought in the same extent that it is. Then there is goodness, transcendental good. Good is being in as much as it confronts love, the will. Everything is good, metaphysically good (I am not speaking of moral goodness). Everything is good, that is to say, apt to be loved, to be an object of love, to the extent to which it is.

Convertibility of Transcendentals
Hence each of these transcendentals is being itself apprehended under a particular aspect. They add nothing real to being, for outside being there is but nonentity. There is no real distinction between being and unity, between being and truth, between being and good. They are “convertible” notions. The distinction between these different intelligible infinities is merely conceptual, virtual, though based on reality.

Good and Evil
[Digression inspired from Preface to Moral Philosophy:
If everything is good in the same measure that it is, what is malum, evil? There is a certain malum in the imperfection of beings, by the fact they have potentialities not actuated, and by accidents preventing potentialities to be actuated, thus preventing a being to reach some perfection that it should possess.

However, real evil, moral evil, is the realm of practical intellect, of ethics, not metaphysics. Moral evil is always the result of an action or omission by a free agent. It is the active destruction of a being, or of something a being possesses, or the preventing of something due to a being in virtue of its nature and of natural moral law. As Mr Mike Flynn (The OFloinn) pointed out to me not long ago, evil does not have metaphysical existence, evil does not exist properly speaking.]

[This is why baldness, for example, is not appropriate to illustrate potency/act and final/efficient causality, because it is not a positive event; it is a defect, something that should normally happen but does not, in this case the growing back of hair after it has fallen. Besides, it is accidental, not substantial; it is not part of the essence and substance of a being, not essential to a being to subsist as such. (Basics on essence, substance and accident are treated in Introduction to Philosophy.)]

Being and Tendency
By the very fact that being is good, it implies in all existents a tendency towards, a desire of this good, that we call “natural” (or consubstantial) inclination, or appetite (appetitus naturalis). The goodness which is coterminous with being endows being itself with a tendency to expand and pass beyond itself, to communicate a surplus. Thus we observe in every natural agent belonging to this sensible universe a tendency to perfect another by transitive action or to perfect itself ontologically by the immanent action of the living organism which builds up itself.
[In beings endowed with intelligence and will] there is a tendency to overflow in knowledge and in love. And in both cases the subject at the same time perfects itself. The superabundance of love, the generosity of being, tends towards itself or others in virtue of a supra-subjective existence, an existence of the intentional order – existence as a gift.

Love is a “natural,” or consubstantial, appetite which proceeds not from knowledge but from the very substance of a being, and which exists in a stone or a tree as well as in man. Now, when a being knows itself, and can say ego, this love also is a natural love, but now as a movement of the will, a tendency or affective overflow towards that object which I will because it is good for me or to which I will good because it is good.

Being and Motion
A tendency is a motion towards the perfection desired, if it is absent. Wherever there is tendency towards a good not already really conjoined with the subject, as a perfection possessed by it or as a friend united with it by presence and community of living, there is motion, change.

Motion forces itself upon the philosopher as an undeniable fact of experience which is apparently incompatible with being as intuitively apprehended by intellect – hence the classical conflict between Heraclitus and Parmenides. We must maintain that being itself, because it involves tendency, involves motion. Being, therefore, must comprehend two levels, that of actual being, being in act, and potential being, being in potency, that is real possibility, real capacity for a particular determination or perfection. It is this distribution of being on two levels which makes possible a metaphysical analysis of motion. But these two levels, act and potency, are themselves essentially analogous.

The First Four Principles of Speculative Reason
Transcendentals (the one, the good, the true) express to the mind nothing but being itself, to which they add nothing save conceptual differences, conceptual aspects. They are convertible but not identical notions, and their names are not synonyms. As transcendentals flow from being in respect of our ideas, other notions as well enter our mind’s field of vision. I mean the first principles of speculative reason, identity (also called non-contradiction in logic), sufficient reason, finality and causality.

Order of First Principles
Order does not mean that these principles are demonstrated from the first, but that we can prove by a reductio ad impossibile, that if any of the first principles of reason is denied you necessarily deny the principle of identity, and if the principle of identity is denied you can neither think nor speak, cannot indeed exist as a thinking being, as a man.

1. Principle of identity
The principle of identity receives different formulations which all have in common that the subject and predicate are the same thing, the transcendental ens, being, but divided in the mind in two different notions. We can say “each being is what it is”, where “each being” is the existent or possible being given to the mind, and “what it is” is its intelligible determination (essence, nature), being as affirmed by the mind. Other formulations are: “every being is of a determinate nature”, or simply “being is being”, or “what exists exists”.

The formula, which can be put also in the negative form “being is not non-being,” is no tautology, it implies an entire metaphysic. A being posited outside its causes, outside nothingness, exercises an activity, an energy which is existence itself. Esse is an act, a perfection, indeed the final perfection in which objects affirm themselves.

2. Principle of sufficient reason
Here also we observe that being divides itself into two objects of thought, two conceptual objects. In the case of the principle of identity, being is taken simply as what exists or can exist, the transcendental ens; now we pass over to being and the transcendental truth, to being as it confronts the intellect.

Our intellectual perception of the bond between ens (being) and verum (truth) implies another distinction: being must either possess its intelligible sufficiency of itself, a se, or derive it from some other being, ab alio. This is a preliminary and approximate statement of the principle of sufficient reason.

The intellect, made for being as intelligible, must possess it complete and fully determined. That which determines an object in respect of intelligibility is that which grounds it in respect of being, that in virtue of which it is. We therefore enunciate the principle of sufficient reason in the general formula: everything which is, to the extent to which it is, possesses a sufficient reason for its being; to put it in another way, it is capable of explaining itself to the intellect. A second formula is: whatever is, is intelligibly determined; whatever is, has that whereby it is.

This principle has a far more general scope and significance than the principle of causality, for it applies in cases in which the efficient cause plays no part. For instance, man’s rationality is the grounds for his ability to laugh, the essence of the triangle is the ground of its properties, and there is no difference of being, no real distinction between the properties of the triangle and its essence, as there is no difference between God’s essence and His existence, His essence is precisely to exist, thus God has in Himself his grounds for being.

Potentiality and the Good
The principle of sufficient reason precedes the division of being into potency and act.

Being and intelligibility go hand in hand and, consequently, all beings other than God must comprise in their metaphysical structure, together with relative nonentity, a factor of relative unintelligibility, that is, potentiality. To this potentiality in all creatures and therefore in all created goods corresponds the dominating indifference of the will, whose necessary object is good as such. The will is unable to will anything without first tending to a good chosen as absolute, as presented by the intellect. From its own determination toward the good as such, the will gives its determination to a particular good for the subject. Thus the principle of sufficient reason enables the freedom of the will. [In morals, though, not only the good as perceived by the subject, but the objective value and objective ends specify a particular good.]

3. Principle of finality
The principle of finality has two different expressions that cover the planes of potency and act.

First aspect: Potency essentially refers to act, potentia dicitur ad actum. Here potency is regarded as passive potency or potentiality in its reference to the act which determines and perfects it. We can conceive potency only in reference to an act. Pure indeterminacy is unthinkable.
In view of the dynamism of being, the fact that every being follows a tendency, an inclination, we affirm that potency has a natural desire, a natural appetite for act. The concept of potency is thus essentially relative and the foreordination of potency to act is finality. It is unthinkable that anything could produce anything. Being produces what it is determined to produce. Determination brings us to ordination and ordination to foreordination. The relation of the subject of change to the determination which actualises it, the relation of a potency to its act is that which imposes upon the mind the notion of finality.

Second aspect: Every agent acts in view of an end, omne agens agit propter finem. This latter statement is concerned with the order of activity, of actuality and perfection. And since of its nature act precedes potency, this is the principal one.

The notion of agent involves in the first place the actuality of a being in act possessing a particular determination and perfection which constitute the being what it is. It also implies that this being communicates an actuality, a perfection either to another in the case of transitive action or to itself in the case of immanent action. (The most purely immanent action is spiritual, for example an act of intellection or will.)

This is the principle of finality in its primary metaphysical significance: Being is love of good, every being is the love of a good, and this love is the very ground of its action. Being tends to good in order to perfect itself or something else, to impart to itself or another a perfection, a surplus. The good to which it thus tends is called an end. It is an end for the agent. And the love of this end is the formal reason of the agent’s action.


Being as agent is reference to and determination to a particular good. And this reference is the very ground of the agent’s operation. Before the action is performed it is determined that the agent shall produce this particular effect, perform this particular action rather than any other. For example, the bird is determined to fly by its essence or nature as a bird.

To be determined to a term presupposes an ordination, a relation to that term. In the case of being as agent, this ordination or determination must exist between the agent and the term of the action before the agent acts and produces its effect. The determination is the ground of the agent’s action, and the ground of the action must precede, at least with a priority of nature, the action itself. To be a bird is to be ordained to the action of flying.

How can there be a relation, an ordination between agent and term before one of them, or both, exist? Only if the action or effect exists as present in thought, with the existence of knowledge. All this follows of necessity from previous considerations. We are compelled to admit that before being posited in their natural existence the agent’s action and therefore his essence alike exist with an existence superior to their merely natural existence, an existence of knowledge or thought.

4. Principle of efficient causality
A species of trinity is constituted by the first principles which cover the entire field of being in all its universality, namely the principles of identity, sufficient reason and finality, that relate respectively to transcendental being, transcendental being and truth, transcendental being and good. Below this level of absolute universality we can study contingent being. And when it contemplates contingent being, being which does not contain in itself the ground of its being, its sufficient reason, the mind catches sight of a fourth self-evident principle, the principle of efficient causality.

The notion of being thus divides into self-existent or absolutely necessary being and being which is not self-existent but contingent. The same division may be expressed also as being in pure act and composite being, being into which enters a factor of potency. Efficient causality applies only to being which contains a potential factor, being therefore which is not a se (of itself, sufficient reason of itself).

Contingent being, being which is not self-existent, being which can be non-existent, this conceptual object also divides before our mind’s eye into two objects conceptually distinct. One of these is what I propose to term “contingent being posited in existence,” the other what I shall term “caused,” that is to say, “having a ground, a sufficient reason other than itself.” When our mind contemplates these two notions we see that in being outside the mind they are necessarily identical. Accordingly we formulate the axiom : Every contingent being has a ground other than itself, exterior to itself, that is to say an efficient cause.

It is a self-evident axiom, like the principles we have already examined, but speaking generally it would seem that the mystery of being deepens when we come to the principle of causality.

If we remain within the intelligible order and respect its mystery, we shall find that it is possible to penetrate a little way into the intelligible mystery, by employing the keys forged by Aristotle, namely potency and act, and recognising the dynamic nature of being, the ontological root of the tendency, inclination and love.

The principle of causality – every contingent* being has a cause – may be expressed more philosophically in terms of potency and act. We shall affirm that: Every being compounded of potency and act in as much as it is potential does not pass of itself to act, does not reduce itself to act. It passes to act by the operation of another being in act which causes the change. Nihil reducit se de potentia in actum.

Many other questions might be discussed concerning efficient causality. The fact should be emphasised that the notion of cause, like that of being, is essentially analogous. We should thus reach the conclusion that God is cause, indeed pre-eminently cause, that it is as the cause of being that reason is compelled to recognise His existence, though He is a cause not like any cause we know.

In the last page are listed a few other axioms, and there are many more to be found in St. Thomas’ Compendium Theologiae.

– Formal causation: “Everything which exists is formed and determined,” or in other terms, “Every determination is a perfection in so far as it is due to form, a limitation in so far as it depends upon matter.”
– Material causation: “Every change presupposes a subject.”
– Act, change: “Operatio sequitur esse. Operation follows being.”

Corollaries of the principle of sufficient reason and the principle of causality:
– That in virtue of which anything is must be greater or at least not less than it. Propter quod unumquodque et illud magis, aut saltem non minus.
– That in virtue of which anything is must be better than it. Id propter quod aliquid est, oportet melius esse.
– That which is by itself (by its essence) is prior to that which is not by itself. Quod est per se (per suam essentiam) prius est eo quod non est per se.
– Whatsoever possesses anything by participation is reducible to that which possesses it by its essence as its principle and cause. Omne quod habet aliquid per participationem reducitur ad id quod habet illud per essentiam sicut in principium et causam.

* Note on the cosmological argument for the existence of God
The principle of causality is that “Every contingent being has a cause.” However, we can hear and read repeated ad nauseam from the legions of atheists and nihilists of this world “Everything has a cause,” which is a falsity, thus a straw man when used as an argument against the existence of God.

Roses and Causes (example of the four types of causes)
The finality of every being is a good; every being tends to perfection. A rose will die in a few days but it will grace the garden and give joy to beholders in its time. And it will not wither and fall without having given its seed (if it is not deprived accidentally of this end**) so that other roses may grace the garden in their turn. The formal cause is in the essence-nature of the rose plant to grow flowers. The material causes are its physical conformation and a suitable soil, light, humidity. The gardener is the efficient cause. In the case of a wild rosebush, it would be, say, Nature… or a mysterious Gardener.

** End: purpose, final cause, teleology