## 1. Life



There are not many sources on the life of Abner. The majority of the
sources are autobiographical passages in his works (especially
*Mostrador de Justicia*). Abner was born around 1260, probably
in the Jewish community of Burgos, one of the major communities in
Castile. While still Jewish, Abner worked as a book trader, a rabbi,
and he may have been a physician as well. During this time he was the
head of a yeshiva (Jewish academy) in Burgos, but we do not know if
this yeshiva was a public institution or just a private group of
students that met in his home. We know from a former pupil, Rabbi
Isaac Pulgar, and from the sources that he utilizes in his works, that
during the Jewish period of his life, Abner was a philosopher, being a
part of the Maimonidean-Averroist trend of Jewish philosophy at the
time.



In spite of the majority opinion of modern
 scholars,[1]
 Abner probably was not a Kabbalist before his conversion to
Christianity. This mistake is based essentially on two sources: the
fact that some of Abner's arguments for the Trinity and Incarnation
can be interpreted as deriving from Kabbalistic sources, and the
existence of another Rabbi Abner (not a common name for Jews of his
time), a Kabbalist whom Rabbi Isaac of Acre cited many times. In my
opinion, Abner's argument for the Trinity and Incarnation is not based
on Kabbalistic sources, but stems from his Neo-Platonic and standard
Christian scriptural
 background.[2]
 Additionally, Abner (the apostate) did not use many important
Kabbalistic
 sources.[3]
 His opinions are not the same as the other Rabbi Abner's (the one
that Rabbi Isaac of Acre quotes), and we can see that the two authors
do not share the same background, nor do they use the same sources,
with Abner utilizing almost entirely sources taken from the Jewish
philosophical and traditional rabbinic
 corpuses.[4]
 almost all of Rabbi Abner's sources are taken from the commentary of
Nahmanides to the Torah, a book that Abner the apostate almost never
quoted. 



The beginning of Abner's doubts about Judaism began with the incident
of a false messiah in Avila in 1295. According to Abner, the Jews of
the community, which is in North Castile, went outside the city to
welcome the messiah, but instead of the messiah they received a
rainfall of crosses that stuck to their clothes. Some of the Jews who
witnessed the miracle went to Abner for advice. This event instilled
in Abner some doubts about the question of the reason for the ongoing
exile of Israel and the truth of Judaism. After twenty-two years of
feeling ambivalent (i.e., around 1317) Abner wrote about his first
revelation in a
 dream.[5]
 In his dream he saw a man that told him to be "a teacher of
righteousness" (*mostrador de justicia*, not
coincidentally the name of Abner's main book) and to bring his people
to freedom from exile. This dream just accents the uncertainty of the
Jewish Rabbi. After three more years of studies he had a second dream
wherein he had the same revelation, this time noticing that on the
clothes the man wore were crosses like the cross of Jesus the
Christian. This dream prompted him toward his final conversion around
1320/1321. After his conversion, Abner became the sacristan of the
collegiate church of Valladolid and devoted himself to the propagation
of Christianity amongst his former fellows Jews (he had come to the
conclusion that conversion to Christianity was the only way to be
saved from the Exile). We know he wrote an extended polemicist oeuvre
and that he took part in the anti-Jewish polemic effort in North
Castile around 1336-1339. There was a public disputation between
Abner and a rabbi that occurred probably around 1335-1336 on the
subject of the prayer of the Jews against the apostates. This dispute
was the main reason for the decree against this part of the Jewish
prayer (*birkat**ha-minim*) by Alfonso XI in 1336. Abner
probably died in 1347 or later.


## 2. Works



Abner's works may be divided into three different categories: polemic,
scientific and philosophic.



Polemic works: *Mostrador**de Justicia* is the earliest
and most important work of those writings of Abner that have survived.
Only a translation (probably by Abner himself) in Castilian exists
today, whereas the original Hebrew was lost. The book starts with a
brief introduction wherein Abner writes about the reasons for his
conversion (the incident in Avila and his two dreams). The main part
of the book is a debate between a Christian (the master) and a Jew
(the rebel). In contrast to other works similar to this type of
polemic debate, in the Mostrador, the rebel does not become a
Christian, and despite his losing the debate, the Jew continues to
believe in his ostensibly false religion. The book is divided into ten
chapters, with each chapter being subdivided into a number of
paragraphs. Each paragraph is a speech by one of the protagonists of
the
 debate.[6]



Summary of the chapters:



I.
 Abner indicated which books could be used as a basis for proof
during polemic debates. In this chapter the master and the rebel agree
that both sides may bring in proofs from philosophical arguments.
 II.
 Abner's proof of the giving of a new law upon the coming of the
Messiah.
 III.
 An explanation and justification for the revelation of a new
law.
 IV.
 The arguments of those who deny that the messiah was to come and
die and bring atonement for the sin of Adam; and what refutes those
arguments.
 V.
 The arguments of the rebel which contradict the master's position
on the Trinity and the Incarnation of the person of the Son in the
human form of the Christ, and the masters answer to those
arguments.
 VI.
 The rebel's arguments against incarnation of the divinity in the
human form of the Christ and how the master tries to refute those
arguments.
 VII.
 An attempt to prove that the hope that the Jews have in the
coming of the prophesied Christ is a false hope, and that Jesus of
Nazareth was the Christ who came according to the time that was
indicated for the coming of the Christ in the books of the prophets
and the sages.
 VIII.
 Arguments of the Jews that the Christ has not yet come, which is
the basis for their claim that the Christians are the people of Edom
or Esau, which was to be destroyed and to fall before the coming of
the Christ; and an attempt to refute those arguments.
 IX.
 An attempt to prove that the hope that the Jews have for the
coming of the Christ at any time is a false hope, and for this reason
the Jews are still in exile from the Land of Israel.
 X.
 Abner's attempt to prove that the Christians, according to the
customs and commandments which they have in their laws, should be
called the Holy Nation of Israel, and that the Jews, according to the
customs and commandments which they have in the laws of the Talmud are
not fit to return to the Land of Israel; and the rebel's attempt to
refute those arguments.


*Responses to the Blasphemer (Teshuvot la-Meharef)*: this book
survived both in the original
 Hebrew[7]
 and in a Castilian
 translation.[8]
 This book is a response to the different letters that Abner's only
known student, Rabbi Isaac Pulgar, wrote against his determinist and
Christian
 writings.[9]
 Abner did not divide this book into formal sections, though the book
contains four main subjects presented in a contiguous fashion: (1) an
introduction wherein Abner attacks his former pupil on his
philosophical position and other personal matters between the two; (2)
the Trinity and how it can be based on philosophy, scripture and
quotes from the Jewish rabbinic literature; (3) the necessary
existence of the incarnation of divinity in the world; and (4) a proof
of the aforementioned Christian beliefs derived from scripture and
other Jewish sources (Talmud and Midrashim). In this last part, which
takes up almost half the book, Abner argues that the messiah had
already come and that Christianity is true.



While Abner's arguments regarding the Trinity and Incarnation are
generally more developed in *Mostrador**de Justicia*,
the philosophical importance of this work resides with his critique of
the Jewish philosopher. Here Abner distinguishes between the regular
Jewish people (that have some hope to become Christian and to be
saved) and Jewish philosophers (like Pulgar). The latter are hopeless
and are left with no religion, mostly due to their opinions that only
the people who attain scientific knowledge have some kind of existence
after death. Due to their feeling elevated over others, these
philosophers have no hope of improving and accepting the truth of
Christianity. Parts of Abner's critique of Jewish philosophers in this
book most probably influenced Crescas.



*Libro de la Ley* (*Book of the Law*). This work
survived only
 fragmentally[10]
 in Castilian. The major argument of Abner in this book is that the
Jewish people forgot the secrets of the Torah, which are manifested by
the Christian doctrines, especially the Trinity.



*Sefer Teshuvot ha-Meshubot* (*The Book of Responses to the
Apostasies*) exists only in
 Hebrew.[11]
 There are three polemic
 letters[12]
 that deal especially with scriptural arguments on the subject of the
coming of the
 messiah.[13]


## 3. The Trinity and Incarnation



The two major subjects of the philosophical polemical works of Abner
are the Trinity and Incarnation. Abner had an original view on the
Trinity. In his opinion, one can prove philosophically the reality of
the
 Trinity.[14]
 He claimed that only the division of the divine source of the world
can explain the diversity of the world. The infinite force of God (the
father) would burn the finite matter of the world if it were not for
some "transformer" that adapted the divine force to the
finitude of matter (the son). Abner distinguished between two parts of
the son. The superior son is part of the transcendent divinity. The
inferior son is the divine essence in all the different parts of the
world. The transformer of the divine force and essence is the superior
son.



Regarding the theory of the divine attributes, Abner also had an
original opinion. He distinguished between the attributes that are the
essence of God and the attributes that are essential to God. The
attributes of the essence of God divide themselves only within the
personas of the Trinity. The rest of the attributes are only essential
to God (and could be attributed to any one of the personas). This
division of the divine attributes influenced Rabbi Hasdai Crescas,who
later influenced Spinoza.



Abner's opinion on Incarnation was also very original. According to
Abner, the essence of God is in the entire world. The world is
composed only of corrupted matter and of divine essence in different
degrees of purity. Even the most corrupted matter has inside itself
some divine essence. The divine essence gives the corporeal form to
matter and produces in it its dimensions. The uniqueness of a human
being is the capacity to purify one's matter, thereby reaching a
higher degree of divine essence. According to Abner, what made Jesus
unique was that he was born of the highest matter, enabling him to
unite with the highest degree of divine essence that a human can
attain. Abner thought that the superior son does not incarnate in this
world. Jesus was only the highest degree of the inferior son that is
present in the essences of the entire world.



The opinion of Abner on Incarnation is closely related to his view of
the doctrine of Original Sin. In Abner's opinion, the reason for the
original sin was Adam's lack of comprehension. Adam thought that his
intellect, which is an incarnation of divinity in people, was God, and
he therefore wrongly concluded that he was God. In order to fix Adam's
error, humanity needed the Torah of Moses, which emphasized the unity
of God in an exaggerated form and therefore explained (somewhat
inaccurately) that God does not incarnate in the World at all. Only
after this critical step, humanity was able to understand that, though
there is divinity in humans, this divinity is not an independent God,
but rather a part of the divine essence in the whole world. The Law of
Moses that came to purify the world from idolatry has some problems.
It does not enable the full emancipation of humanity from sin and
error. Abner claimed that the negation of the incarnation of God in
the world leads to negating the possibility of life after death. The
possibility of life after death comes from understanding the
incarnation of divinity in all humans. Negating life after death
causes immorality. The Torah has to put up with all these inaccuracies
in order to achieve its main goal, which is taking humanity out of the
sin of idolatry (by believing that God is one). The outcome, though
better than its predecessor, is ultimately a lost situation which
humanity cannot overcome on its own. For that reason, God sent Jesus
(who was born with a higher degree of matter and divine essence). Due
to the divinity within Jesus, his miracles and his resurrection,
people are able to understand that within everything in the world
there is some divine essence that is part of the inferior son, and
that the origin of all the divinity in the world is the superior son.
This understanding enables salvation from the original sin and
represents a true understanding of the relation between God and the
world. The role of the sacramentental Mass is to remind us of the
divine aspect of Jesus' essence, as well as of all the miracles that
Jesus performed and to continue their influence in our present
time.



We see that this opinion regarding the Trinity and Incarnation
contradict the official dogma of the Catholic Church at the time of
Abner. In his opinion, the incarnation of divinity in Jesus did not
bypass the regular process of the emanation of the divine essence in
the world. Rather, the manifestation of Jesus represented the pinnacle
of incarnation of divinity, which, though indeed present in the entire
world, yet in Jesus occurred in the purest form possible. This opinion
of Abner, similar to his other philosophical views, was a part of the
radical Neo-Platonic interpretation of Christianity. The difference
between him and the other Neo-Platonic Christian philosophers, like
Master Eckard, is the different sources from which they were
influenced. Abner did not utilize the traditional Neo-Platonic
Christian sources, like Dionysius the Areopagite. We do not see in any
part of his work that he was aware of the existence of these sources.
On the other hand, Abner did utilize some Arabic and Jewish sources.
The origin of his uncommon position on Christianity is found in his
opposition to the common Aristotelian-Maimonidean-Averroist trend of
Jewish philosophy. Abner, similar to Spinoza after him, thought that
the explanations of these thinkers on the question of the creation of
the world by a perfect God were not sufficient and ultimately
inaccurate. In place of these responses, Abner proposed his radical
interpretation of the Christian doctrine of the Trinity, an
interpretation that was uninfluenced by the theological Christian
tradition. 


## 4. Determinism



One of the more important philosophical opinions of Abner was his
deterministic
 view.[15]
 Abner devoted his book *Ofrenda de Zelos* (*Minhat*
*Kena'ot* in the original lost Hebrew text), along with other
works that have since been lost, to the question of determinism and
free
 will.[16]
 In the beginning of this book, Abner describes the opinion of his
former pupil Rabbi Isaac Pulgar, who denies God's foreknowledge of
human decisions. After the explication of this opinion and its
negation, Abner explains his deterministic opinion. Abner believed
that people have free will in a limited sense, but act in a determined
way in the broader sense. People are free in their relation to
themselves, meaning that if a person is separated from the causes that
influence him or her (e.g., education, society's influences) while
debating between two options, one is then really free to choose either
of the two options. In this specific case a person can then utilize
his or her will and choose freely between the two options. However, if
one takes into account all the causes that influence his or her will,
we may conclude that these causes limits that person's will to only
one of the two options. In the opinion of Abner, people are like wax,
as follows: Wax may be melted and sculpted into many different shapes.
However, the person who sculpts the wax determines its present form as
only one of those options. The same is true about people: In
themselves, they have the ability to choose between different
possibilities, but their relation to the outside world determines
their choices. We can see from this example how strong the determinist
view of Abner was. It is important to note that Abner defines the will
of people as an accord between the attractive force and the
imagination, two forces common to humans and animals.



Abner explains in the same way the meaning of possibility and
accident. Things are only possible in their relation to themselves. In
relation to the entire world and its causality, everything is truly
determined. Accidents are only accidents relative to the seeming
unlikelihood of their occurrence. However, relative to all the causal
processes of the world, we see that even in the most unusual of
circumstances the occurrence of what appears to be an accident in fact
had to happen. In short, there are no accidents (according to the
popular meaning of accident) for Abner.



This deterministic description of the world (based on rational
arguments) resolves the theological problem of the contradiction
between the free will of people and the foreknowledge of God. In the
opinion of Abner free will does not really exist. For him, God is the
first cause; He knows all the laws of the world and therefore knows
everything that He has determined.



This deterministic description leads to two theological problems. The
first is why God sent commandments to people who cannot truly decide
whether to obey them or disobey them. The second question that arises
is how people can receive reward or punishment for actions and
decisions that they do not really have any control over? Abner answers
the second question by explaining that forbidden things are naturally
bad. The punishment of the sinner is not a special act of divine
providence; rather it is the natural consequence of his bad action.
This leads us to the answer to the first question. According to Abner,
the goal of the Torah is to influence people to do what is right. The
Torah and prophets (and God who sent them) act in the world in
conformity to His nature. The only way to influence someone to do
something is to give him enough causes to do it. The Torah is only
another cause that influences people to do what is good. Abner
compares reward and punishment to a father that obligates his son to
take medication. The medicine will always work even if the son takes
it unhappily. The same is true with regard to all actions of people.
When people do what is right, they believe they will receive a reward,
while if they do what is wrong, they believe they will receive a
punishment--even if they do not essentially have the choice to do
anything else. 



It is interesting to note that this philosophical book that Abner
wrote at the end of his life, more than twenty years after his
conversion, is almost without Christian
 references.[17]
 In spite of this, the book is full of references to Jewish sources,
including the Talmud and quotations of Jewish authorities like
 Maimonides.[18]
 We see that Abner, even many years after his conversion, wrote to the
Jewish community and was part of the internal Jewish debate about the
question of determinism. In fact, Abner is the first medieval Jewish
philosopher to argue for a deterministic explanation of the world. His
opinion influenced Rabbi Hasdai Crescas (who paraphrased an important
part of *Ofrenda de Zelos* in his major philosophical work
*The Light of the
 Lord*[19]),
 and through him, Spinoza. Some Jewish philosophers, like Rabbi Isaac
Pulgar, Rabbi Mosses from Narbonne, and Rabbi Josef Ben Shem
 Tov[20]
 respond explicitly to the determinist opinion of Abner, such that
there is no doubt that his opinion had a major influence on the
internal Jewish debate on the question of free will throughout the
14th and 15th centuries. 


## 5. Critics of the Aristotelian science



As we stated before, the major work of science of Abner (*the New
Philosophy*) is lost. We can still try to reconstruct some of his
scientific opinions through some parts of his other works,
specifically the existing work *Meyasher Aqob*, Rabbi Isaac
Pulgar's brief summary of the lost work, and some scientific passages
in *Mostrador de
 Justicia*.[21]



The first interesting opinion of Abner is his view on prime matter.
Abner denied a necessary link, which the Aristotelians affirmed,
between bodies and accidents (magnitude, weight, quantity, etc.),
maintaining that a body untainted by all these accidents can
nonetheless have actual existence. He explicated his view in the
dogmatic context of the question of the rite of
 Mass.[22]
 The rebel's main philosophical arguments against the Mass are as
follows: (1) How can several bodies occupy the same place? (2) How can
Jesus' body be in the bread and wine without changing them? (3) How
can the same body be two different materials at the same time? (4) How
can one debase Jesus by eating and digesting him? At the start of his
answer Abner emphasizes that the Mass is miraculous. Nevertheless, he
does go on to offer a scientific explanation of transubstantiation.
For Abner, everybody has a layer of pure divine existence, to which
are superadded other forms and accidents; but if the body is stripped
of all of these accretions it will be reduced to the original divine
substance only. In this state the body will have no boundary,
quantity, or weight to occupy the universe, and consequently is
infinite. This body is the foundation of the entire material world,
and normally--with the exception of the sacrament of the Mass and
Incarnation--it does not exist without accidents (at least not in
the sublunary world). This matter is identified with the flesh of
Jesus, which has divine existence only, which means that Jesus' body
is identified with prime matter.



The above description eliminates for Abner all of the difficulties
posed by the rebel. The problem of the co-presence of two bodies in
one place is eliminated, because all bodies, once they have been
stripped of their form and accidents, incorporate the infinite body of
Jesus, which fills the entire universe. After these forms have been
removed, the bread and wine are identified with Jesus' body. The very
same principle eliminates the problem of the simultaneous existence of
Jesus' body in several places, since his body fills the entire
universe and transcends all definitions of place. Because his body
also transcends the definition of quantity, the problem of limited
quantity is removed as well.



Another subject about which Abner critiques Aristotelian science is
the definition of place and the relation between place and body. In
the thought of Aristotle, the definition of place is 'the limit
of the encompassing body'. In his opinion, place has an
important role in movement. The definition of a natural movement is
the movement of a body to its natural place in the world. Aristotle
explains that both the natural place attracts the body and that the
body moves on his own to its natural place.



Abner distinguishes between the physical object and extension or
dimension. According to Abner, dimension is "a simple and subtle
quantity detached from all movable bodies"; in other words, it
is space, independent of any physical body. Dimension is measurable
per se, and is not linked to what occupies it. Nevertheless, Abner's
definition of place is still associated with body: "place"
is the dimension occupied by a body, and it is the body that turns it
into "place." According to Abner, the movement of bodies
is not due to their being attracted to some place where they must rest
before resuming their movement; rather, they move because of the
interaction of several forces, quite independent of any particular
place. A body that is thrown upward rises, but if it suddenly begins
to fall because of an opposing force, there would not be a moment of
rest between the two opposing motions.



Thus Abner dismisses Aristotle's concept that a body is attracted to
its natural place. Different places are not characterized by different
qualities (inasmuch as all places are equal and are merely points in
space). Hence a body has no cause to move to a particular place and no
place is a final cause of its motion.



We know from Rabbi Isaac Pulgar that Abner also criticized the
opinions of Aristotle on the possibility of a void and argues for the
existence of voids in his lost scientific book *The New
Philosophy*. Because of the influence of Abner on Rabbi Hasdai
Crescas, we can assume that his criticism is closely related to the
criticism of Crescas in the beginning of the first speech of *Or
Hashem*



Abner wrote his criticism of Artistotelian science at the beginning of
the 14th century, approximately the same time that Ockham
wrote his criticism of this science. In the writing and the thought of
Abner we do not see any kind of influence of Ockham or of other late
scholastics (the only scholastic philosopher that he cites is Thomas
Aquinas and there are no quotations from Christian sources on a
scientific subject). It is interesting to note that the systematic
criticism of Aristotelian science started approximately at the same
time in the Jewish milieu (with the writings of Abner) and in the
Christian milieu, with probably no relation one to the other.



Abner's criticism of Aristotelian science had an important influence
on Crescas's thought, and through him to Pico Della Mirandola and
general Western philosophy.


## 6. The influence of Abner



One must distinguish between two kinds of influence Abner had. Abner
influenced with his polemical works the Jewish-Christian debate until
the end of the Middle Ages. Some born-Christians, like Alfonso de
Espina, and especially Jewish apostates, like Pablo de Santa Maria,
utilized his polemical works. Against this trend, there are more than
five Jewish polemicist works that explicitly answer the polemical
arguments of
 Abner.[23]
 Despite the utilization of Abner in debates, his works had almost no
philosophical influence on Christian theology because the Christian
participants in the debates utilized the quotations of the Jewish
sources by Abner and not his theological arguments as such, which in
their content were very different from the official Catholic
dogma.



The second way in which Abner had lasting influence was on the purely
philosophical plane. It should be noted that the direct philosophical
influence of Abner was only on the Jewish community. In fact we do not
see that any Christian philosophers read the works of Jewish apostates
in any other forum apart from the purely polemical one. By contrast,
in the Jewish community the works of Abner had an important impact
until the expulsion of the Jews from Spain in 1492. The deterministic
opinion of Abner is with no doubt one of the major causes to the
extensive number of works written on this subject in the
14th and 15th centuries by Jewish philosophers.
For the most part, these works were against the opinion of Abner. The
most impressive philosophical influence of Abner was on Rabbi Hasdai
Crescas (died in 1410/1411). Crescas was the main Jewish philosopher
during the end of the Middle Ages. Despite their opposite positions in
the Jewish-Christian debate (Crescas wrote one of the more
philosophical anti-Christian
 works),[24]
 Crescas borrowed some of the major original philosophical opinions of
Abner, including determinism, the difference between the attributes of
the essence and the attributes that are essential, and the criticism
of Aristotelian science. With regard to this entire subject, Crescas
molded his opinion using Abner combined with other sources. In spite
of this important change, we can clearly see signs of the philosophy
of Abner in the writing of Crescas, and these signs constitute nearly
all the post medieval influence of Abner on Jewish and general Western
philosophy.