Alexander the Great, Jesus, and David Marshall: A Simpleton's Approach to History

Alexander Mosaic at Pompeii (ca. 100  BCE?)
If you ever engage in arguments about the historical Jesus, it will only be a matter of time before someone invokes Alexander the Great or some other ancient figure to charge those who doubt claims of Jesus' supernatural activities with undue skepticism.
Those who cite Alexander the Great often assume that his acts are so well established historically that doubting them is a sign of undue skepticism. And if you doubt that Alexander the Great performed certain feats, then any doubts about Jesus’ supernatural activities can be dismissed because of similar undue skepticism.
This essay will show that those who think that Jesus’ activities are as well established as those of Alexander simply don’t know Alexander scholarship well. In addition, I will show that many or most of Alexander’s exploits cannot be verified because they depend on secondary and tertiary sources whose claims are difficult to corroborate.
In my response to Travis James Campbell I challenged the idea that we had “existing knowledge” of an empty tomb or Jesus’ resurrection as follows (Craig v. McCullagh):
 “Of course, we have no ‘existing knowledge’ that there was an empty tomb, or that Jesus resurrected.  These are simply claims made by ancient authors. We have no existing knowledge that people resurrect, but that does not stop Craig from positing something that is not ‘existing knowledge.’” 
David Marshall, however, thought I was being unduly skeptical and so presented this challenge (Marshall's response):
“By that standard, we also have no ‘existing knowledge’ that Alexander the Great faced elephants on the battlefield in India, or that Confucius climbed Mount Tai in the state of Lu.  These, too, are ‘simply claims made by ancient authors.’”
Marshall here is presumably referring to the famous Battle of the Hydaspes River (site is now the Jhelum River in Pakistan) where ancient sources say that Alexander defeated, in 326 BCE, an Indian king named Porus, who included a contingent of elephants in his forces.
Depiction of the Battle of the Hydaspes by A. Castaigne (1861-1929)
As I will demonstrate, Marshall’s claim that “Alexander the Great faced elephants on the battlefield in India” should not be called “existing knowledge.”

First, I don’t usually use the term “existing knowledge,” and my criticism pertained to the use of it by Craig and Campbell. I prefer to speak of known phenomena/causes and unknown phenomena/causes when referring to the pool of data that can be used in scientific historical explanation.
For me, any “existing knowledge” is based on direct empirical and/or logical evidence for the occurrence of a general phenomenon. For example, death is part of our pool of existing knowledge, as is war, hunger, famine, etc. All of these can be detected empirically, and many can be generated and/or repeated easily in our experience. 
Similarly, one can detect the existence of India/Pakistan and elephants empirically, and one can easily test to see that elephants can be used in battle just as horses can be. Thus, the use of elephants in battle can be said to be a known phenomenon. It is attested empirically, and it is testable today. Therefore, it may be used to explain historical events when the evidence so warrants.
Supernatural resurrections, as a general phenomenon, are not known to occur today. Even W. L. Craig and C. Behan McCullagh, who were the subjects of my initial discussion, might admit that. 
Empty tombs are a known phenomenon, but not empty tombs due to some supernatural event. All the empty tombs known to exist are due to natural processes, and we can repeat that process by simply removing a body from a tomb. 
Thus, tombs emptied supernaturally or people resurrected supernaturally are not at all analogous to any “existing knowledge” of “elephants in war,” tombs emptied naturally, etc.
Marshall often appeals to anecdotes to justify his use of supernatural phenomena in historical explanation. However,  anything we call “existing knowledge” DOES NOT DEPEND ON ANECDOTES FOR VERIFICATION.  “Existing knowledge” should be a phenomenon or cause generally verifiable empirically or based on known causes and phenomena.

A recurrent problem with Marshall’s methodology is that he applies the word “KNOWLEDGE/KNOW” to conclusions with a very wide range of certainty. Consider the two following statements:
A. I know that I exist (ala Descartes)
B. I know that Alexander the Great faced elephants on the battlefield in India
Conclusion A is a direct empirical and logical conclusion, and so it is definitely “existing knowledge,” if one pardons the pun.
To say that I am as certain that Alexander faced elephants in India as I am of my own existence simply shows that Marshall is using the word “KNOW” far too liberally and inconsistently to be useful. 
That is why I also distinguish between “knowledge” and “belief” in delineating my historical epistemology. I further distinguish between reasonable and unreasonable beliefs (The End of Biblical Studies, pp. 114ff).
I can say, at best, that I BELIEVE that Alexander faced elephants on the battlefield in India, but it would be absurd to say that I KNOW that he did.
What Marshall really is saying is that HE BELIEVES certain authorities who make that claim. Indeed, Marshall seems to be assuming the following to establish his existing knowledge of Alexander facing elephants:
 “If Text A says Alexander did X or is Y, then Alexander did X or is Y.”
This is a simpleton’s approach to history. This, of course, is also a very common logical flaw known as an argument from authority, which usually is inadmissible unless there is corroborating evidence. By Marshall's standard, I can say that I KNOW that Alexander was the son of Zeus or Heracles just as much as I KNOW that I exist.
I have no expertise in Chinese literature or history, and so I cannot evaluate Marshall’s claim that “Confucius climbed Mount Tai in the state of Lu.” However, I suspect that claim involves some other version of this rationale: “Authority A says Confucius climbed Mount Tai in the state of Lu, and so  I KNOW Confucius climbed Mount Tai in the state of Lu.”

As I have repeatedly noted in DC posts, Marshall is notorious for being ill-read and not checking primary sources. His statements about Alexander the Great are a good case in point.
The fact is that the state of Alexander scholarship is not as stable as he may suppose, and revising a lot of assumptions previously held to be near sacred has occurred in the last few decades. I started to grapple with the history of Alexander while completing a minor in Classics at the University of Arizona, and I learned quickly how difficult it was to establish much of anything about Alexander.
Frank Holt, a prominent Alexander historian and professor of ancient history at the University of Houston, summarizes some of these issues in his article “Alexander the Great Today: In the Interest of Historical Accuracy?” Ancient History Bulletin 13, no. 2 (1999):111-117.
Based on that and other scholarly discussions, I can identify at least three basic streams of Alexander scholarship today:
A. The historiography associated with W. W. Tarn, who authored a two-volume biography, Alexander the Great (Cambridge: Cambridge University Press, 1948), which magnified his accomplishment and diminished his faults.
B. A revisionist view, which de-heroicizes Alexander, and is represented by the Harvard historian, Ernst Badian. More recent proponents include Ian Worthington, and also A. B. Bosworth and E. J. Baynham, editors of Alexander the Great in Fact and Fiction (New York: Oxford University Press, 2000).
C. A mediating position represented by Frank Holt, author of among many works, Alexander the Great and the Mystery of the Elephant Medallions (2003).
As with Jesus studies, an orthodox view of Alexander developed by the middle of the twentieth century, and that was represented by Tarn’s heroic, wise, and virtuous Alexander.
That hagiographic view began to change, particularly with the work of Harvard historian Ernst Badian (1925-2010).  When commenting on that romantic view of Alexander, Badian noted the degree to which it had become orthodox in comparison to his own revisionism:
“...many of us remember a time when it was impossible to get an article questioning that interpretation into a professional journal in this country” (“The Alexander Romance, New York Review of Books 21, no. 4 (September 9, 1971), p. 9.
Ernst Badian
Since the time of Tarn, developments similar to those that have taken place in biblical studies have occurred in Alexander scholarship. The nature of the sources has become increasingly under question because we often don’t have the means to verify which of Alexander’s exploits actually happened or which were just part of an ancient pro-Alexander propaganda machine, the result of uncritical acceptance of previous traditions, etc.

In general, the main extant sources for Alexander consist of biographies written hundreds of years after he lived.  These are often divided into the following according to Elizabeth Baynham (Brill’s Companion to Alexander the Great, p. 21), from which I am adapting these categories:
I. “Vulgate Tradition” associated with four historians:
A. Diodorus Siculus (1st c. BCE)
B. Quintus Curtius Rufus (1st c. CE)
C.  Justin’s Epitome of Pompeius Trogus (3rd c. CE)
D. The Historical Section of the Metz Epitome (ca. 1300 CE)
II. Non-Vulgate Tradition, which can include
A. Plutarch of Chaeronea (1st c. CE), author of the Life of Alexander                   
B. Arrian of Nicomedia (2nd c. CE), and author of the Anabasis of Alexander, perhaps still the most authoritative source.

It is the Non-Vulgate tradition that is usually regarded as of higher credibility. Others argue that these distinctions are not very useful or must be used with great caution.
All of those extant sources are, in turn, apparently based on earlier sources. Arrian, for example, explicitly names Ptolemy son of Lagus (367-283 BCE; one of Alexander’s military commanders and later king of Egypt) and Aristobulus of Cassandreia (ca. 375-301 BCE), as his main sources. See further: Sources for Alexander
However, verifying what is true in any of the extant ancient historians is very difficult for a modern historian.

Anyone who spends any time reading the ancient sources for Alexander will encounter ancient historians who criticize their counterparts or predecessors at some points.  These sorts of criticisms make it difficult for us to know who is telling the truth about anything.
Frank Holt, (Elephant Medallions, p. 18) evaluates the main sources as follows (omitting the Metz Epitome from my list):
 “Each of these five narrative treatments of Alexander’s reign claims to be a serious work of history or biography; but all five contradict one another on fundamental matters and cannot be considered absolutely reliable unless somehow corroborated by other evidence.”
If we focus on Arrian, the most authoritative source for the Battle of the Hydaspes River, we should heed what he says in the very first sentence of his work (Anabasis 1.1):
“Wherever Ptolemy son of Lagus and Aristobulus son of Aristobulus have both given the same accounts of Alexander son of Philip, it is my practice to record what they say as completely true, but where they differ, to select the version I regard as more trustworthy and also better worth telling.”
So, Arrian regards “as completely true” [Greek: ὡς πάντῃ ἀληθῆ] any report where Ptolemy and Aristobulus agree.  This may seem reasonable, but agreement between sources does not constitute proof of historicity. It also matters the type of agreement and how independent the agreement is.
The fact is that any two ancient sources can agree on things that Marshall and others probably would not say occurred historically about the actions of Muhammad, Krishna, Zeus, etc.
When they disagree, then Arrian uses the following procedure:
A. Select WHAT ARRIAN regards as more trustworthy;
But Arrian does not always tell us WHY he regards one story as more trustworthy when Ptolemy disagrees with Aristobulus. 
Nor can we always verify whether Arrian’s conclusion is historically valid.  Indeed, it would be difficult to see how Arrian, writing in the second century CE, himself verified which, if any, of his sources, was telling the truth about anything that happened some 400 years earlier. The problem of trusting a concatenation of sources, of course, was well pointed out by the philosopher Karl Popper in  his Conjectures and Refutations: The Growth of Scientific Knowledge (London: Routledge, 2002), pp. 29–30.
Procedure B is more troubling because it suggests the use of some artistic license or selection for some other reason other than pure historicity.
When Arrian does give us a reason for trusting Ptolemy, it is not very compelling. For example, he says of Ptolemy (Anabasis 1.2-3):
“ he himself was a king, mendacity would have been more dishonourable for him than for anyone else; again, both [Ptolemy and Aristobulus] wrote when Alexander was dead and neither was under any constraint or hope of gain to make him set down to anything but what actually happened.”
Note that Arrian assumes that kings are more trustworthy, when we have plenty of examples that this was not the case.
Arrian also says that the death of Alexander made it unlikely that these chroniclers would have anything to gain, when we can conjure up reasons for why it might be even more feasible to lie about people who are no longer alive to contradict us.
Yet,  Arrian sometimes says that both Ptolemy and Aristobulus are not necessarily trustworthy even if they were both eyewitnesses to Alexander’s life. 
Consider the case of Callisthenes, one of Alexander’s own official historians who later displeased Alexander. Arrian (Anabasis 4.14.3-4) notes the contradictory accounts of what happened to Callisthenes:
“As for Callisthenes, Aristobulus says that he was bound with fetters and carried round with the army, but at length died of sickness. Ptolemy son of Lagus that he was racked and put to death by hanging. Thus, not even those whose narratives are entirely trustworthy and who actually accompanied Alexander at that time agree in their accounts of events which were public and within their own knowledge.”
Arrian sometimes disputes the very presence of certain eyewitnesses in crucial events in Alexander’s life. For example, Arrian (Anabasis 6.11.8) disputes the claim that Ptolemy’s rescue of Alexander at a crucial battle (at the fortress of Malli in India) resulted in Ptolemy being named Ptolemy Soter (= Savior):
“But in my own estimation the greatest error of the historians of Alexander is this: some recorded that Ptolemy son of Lagus mounted with Alexander up the ladder together with Peucestas, and held his shield over him when he had fallen, and that for this reason he was named Saviour, and yet Ptolemy himself has recorded that he was not so much present in this action, but was at the head of his own force, fighting other battles against other barbarians.”
If so, how can we be sure that the so-called eyewitnesses to any battle were even present where historians place them? How do we know Arrian was right?
So, I wonder how Marshall KNOWS what Alexander did and did not do when Arrian says that he sometimes does not know.
And not all modern historians are enamored of Arrian’s reliability.  Elizabeth Baynham (Brill’s Companion to Alexander the Great, p. 8) a recognized scholar of Alexander, remarks:
“...Arrian’s apparent desire to follow such obviously pro-Alexander accounts, has also rendered the reliability of his own history vulnerable.”
She adds (Brill’s Companion to Alexander the Great, p. 8):
“One needs to exercise caution...ancient authors often pass on the statements of others without reading the work for themselves.”
This, of course, also often describes exactly how Marshall works.

I will not go into detail into the messy history of the texts of the Alexander historians. But let me give you one example of how Marshall’s simpleton’s claim of “existing knowledge” does not reckon with the dates of the actual manuscripts of those histories.
P. A. Brunt, the editor of the 1976 Loeb edition of Arrian’s Anabasis (Volume 1, p. xiv), notes that all the extant manuscripts of Arrian’s Anabasis “were copied from an extant codex in Vienna (A), written about A.D. 1200.”
So, it is often difficult to determine what was added or subtracted between the time that these histories were supposedly written, and the time when the actual surviving manuscripts were copied. 
But apparently Marshall KNOWS that this manuscript from 1200 CE preserves exactly what was in Arrian’s original, and so perhaps that also is why he can say that what that manuscript from 1200 CE says about Alexander constitutes “existing knowledge.”
For the moment and only for the sake of argument, I will assume that those Medieval/Renaissance manuscripts generally represent those ancient histories.

Despite these problems with the sources, the existence of Alexander is a reasonable belief because he has wide and independent attestation from all types of sources, and not just those of his own followers.
Some of these sources date from his own time, and are attested archaeologically, not just from later accounts. So, we don’t just have to depend on later historians such as Plutarch and Arrian.
For example, reliefs at the Shrine of the Bark at Luxor in Egypt mention Alexander by name, and depict him artistically during his lifetime (ca. 330-325 BCE). That would confirm his presence in Egypt mentioned by all major ancient sources.
Alexander Shrine at Luxor, Egypt
We also have a Mesopotamian tablet, now at the British Museum and designated as BM 36761, which mentions Alexander by name, and refers to his entry into Babylon (See Mesopotamian evidence):
-Akkadian (BM 36761, Reverse, line 11): A-lek-sa-an-dar-ri-is LUGAL ŠÚ ana E.KI K[U4
-English: "Alexander, the king of the world, entered Babylon"
Of course, Alexander is also mentioned or referenced in the Bible itself (1 Maccabees 1:1-7; Daniel 8:4-8, 21).
The claim found in Plutarch and Arrian that Alexander conquered Babylon is paralleled by this Mesopotamian source, which is not a Greek source or dependent on a Greek source or cannot be said to have been written by a Greek follower of Alexander.
When Egyptian and Mesopotamian sources, which are not otherwise dependent on each other, say the equivalent of “Alexander was here” during his lifetime, then it is reasonable to believe that there existed a man named Alexander who was present at those places.
That is why it is unfair to compare Jesus to Alexander in terms of historical evidence for their existence. There is nothing outside of later Christian sources saying Jesus was anywhere in his lifetime. Nothing in the New Testament is fully contemporary with Jesus.
There also are no Roman or Greek sources saying that there was even a group who believed that Jesus lived or did anything the Gospels allege about him. There is no archaeological evidence of his activities or of the activities of his group from Jesus’ supposed lifetime.
That absence of evidence is curious because, when speaking of Christianity, Acts 28:22 (RSV) says “everywhere it is spoken against.” More traces should remain in the first century of a group that everyone was speaking against.
In the case of Alexander, his fame was present in a wide range of sources as is expected of someone who was said to have conquered the known world. Alexander was closer to someone “everywhere spoken about” and there is independent corroborating evidence to confirm that.

The reasonable belief that Alexander existed does not mean that we can establish the historicity of everything that is reported about him.
Arrian’s Anabasis (3.3.4-4.2) explains how Alexander managed to find his way to the Oracle of Zeus-Ammon in Egypt, given the dearth of landmarks out in the sandy desert. Arrian remarks:
“Now Ptolemy son of Lagos says that two serpents preceded the army giving voice, and Alexander told his leaders to follow them and trust the divinity; and the serpents led they way to the oracle and back again. 
But Aristobulus agrees with the more common and prevalent version, that two crows flying in advance of the army, acted as guides to Alexander.
That some divine help was given him I can confidently assert, because probability suggests it too; but the exact truth of the story cannot be told; that is precluded by the way in which different writers about Alexander have given different accounts.”
So, these are the sources that Marshall wishes us to trust about Alexander’s exploits? But perhaps Marshall can argue that since we have at least two sources that agree that serpents can talk (Genesis 3 and Ptolemy), then we should take this as evidence that it really happened.
And since Ptolemy was a king, then he would not be as likely to lie about talking serpents, and so maybe he is more credible than Aristobulus on this issue.

Given Mashall’s nebulous criteria for establishing “existing knowledge,” perhaps he may also reckon Alexander’s divine origin as “existing knowledge.”
According to Plutarch, Alexander was the product of a union between a god and a human mother (cf. Jesus). He tells us (Alexander 1.3-2.4):
“As for the lineage of Alexander, on his father’s side, he was a descendant of Heracles through Caranus, and on his mother’s side a descendant of Aeacus through Neptolemus; this is accepted without any question.” [my emphasis]
Given that there is a consensus, according to Plutarch, that Alexander’s ancestors included the god Heracles (= Hercules), then perhaps Marshall also can call this “existing knowledge.”
Plutarch (Alexander 2.4) explains that, Philip, Alexander’s putative human father, suspected that his wife, Olympias, was having sex with a god, and that “a serpent was once seen lying stretched out by the side of Olympias as she slept.”
Moreover, Plutarch (Alexander 3.2)  cites another author named Eratosthenes as claiming that Olympias “told him [Alexander] and him alone the secret of his begetting and bade him have purposes worthy of his birth.”
According to Plutarch, other ancient historians, however, scoffed at this idea and quoted Olympias as repudiating it.  Yet, Arrian (Anabasis 4.10.2-3), says:
“Alexander’s share in divinity did not depend on Olympias’ invention about his birth, but on the account he would write and publish in Alexander’s interest.”
Other accounts indicate that Alexander did believe that his father was a god, and more specifically Zeus. Thus, Arrian (Anabasis 7.29.3) says: “Alexander’s practice of referring to his own birth to a god was not in my opinion a grave fault on his part.”  Later, Arrian (Anabasis 7.30.2) says: “...I do not believe that a man peerless among mankind would have been born without divine agency.”
Likewise, Plutarch says that Alexander was convinced of his own divinity (Alexander 28.1). Alexander was known as a healer, and prophecies about his exploits were fulfilled (see Plutarch, Alexander 17.2-3).
Secular scholars are absolutely consistent in treating both Alexander and Jesus as non-divine beings.  In neither case are any claims to supernatural origin or activities accorded the status of “existing knowledge.”
But, if Marshall is willing to believe, on the basis of Luke and Matthew, that Jesus was born of a union of a god and a human mother, then surely he should believe that Alexander, whose extraordinary and unprecedented feats are actually better documented, had a divine birth on the basis of Plutarch and Arrian.
Perhaps Alexander’s divine birth should even be called “existing knowledge” since Marshall presumably deems Plutarch and Arrian as credible sources about Alexander facing elephants. If they are credible about that, then who are we to question them about Alexander’s divine birth?

Marshall does not specify what sources he uses to support his claim that “Alexander the Great faced elephants on the battlefield in India.” As mentioned, Marshall is presumably referring to the famous Battle of the Hydaspes in what is now Pakistan and dated to around May of 326 BCE.  Alexander is said to have defeated Porus, an Indian king who had a contingent of elephants as part of his forces. See video depiction:      

There are usually two main sources used for this story:
A. Plutarch’s Life of Alexander 60
B. Arrian’s Anabasis 5.11-18
As mentioned, these sources date from hundreds of years later, and and scholars still debate the historical merits of these sources.
Plutarch (Alexander, 60.1) says that he possessed letters from Alexander himself: “Of his campaign against Porus he himself has given an account in his letters.”
But how would Marshall verify that Plutarch’s claim is true, especially as those letters are not extant?   And how would Plutarch, who wrote in the first century, verify that those letters written more than 300 years before him, were actually written by Alexander? As it is, pseudepigraphy was rampant in the ancient world, as is attested by para-biblical books attributed to Enoch, Elijah, The Twelve Patriarchs, etc.
It is for these and other reasons that I agree with J. R. Hamilton (“The Cavalry Battle at the Hydaspes,” Journal of Hellenic Studies 76 [1956] p. 26): “Plutarch, even if the letter of Alexander on which he bases his account is genuine, treats the battle itself in too summary a fashion to be of much value.”
If so, that really leaves us with only Arrian as the main source for the Battle of the Hydaspes.
But Arrian also has his problems. There is a debate between Tarn and other scholars about how accurately Arrian depicts that battle. Thus, Hamilton, who supports the accuracy of Arrian, remarks (“The Cavalry Battle at the Hydaspes," p. 26):
“...if Tarn’s interpretation of the operations is accepted, Arrian must be held to have misunderstood his sources on several important points and to have failed to make Alexander’s tactics intelligible.”
So, how does Marshall ever come to think that anything said about elephants is really “existing knowledge” rather than just a matter of trusting a source whose veracity he cannot verify?

The problem of trusting Arrian and Plutarch about Alexander’s exploits is that we can also detect a tradition to magnify the exploits of heroes, and have them do things that are improbable.
For example, once one reads enough Greek literature, one finds that fighting animals and suffering great injuries are recurrent themes with heroic figures. 
Plutarch (Alexander, 8.2) says that Alexander was so enamored of the Iliad, the paradigm of all Greek epics of heroism, that he kept a copy under his pillow.  Arrian (Anabasis, 3.3.2) tells us that Alexander “sought to rival Perseus and Heracles” in his exploits. 
So, it is not beyond possibility that historians seeking his favor would model him after Alexander’s own heroes. After all, it is reported that Callisthenes, an official historian, was executed or died in prison after displeasing Alexander.  In any case, we have the following heroic exploits reported:
-Alexander fighting a lion (Plutarch, Alexander 40.4).
 -Alexander was shot with an arrow in the leg “so that splinters of the large bone came out” (Plutarch, Alexander 45.3), but somehow Alexander was later still able cross a river and pursue the enemy.
-Alexander was struck in the chest by an arrow so that air  (pneuma) and blood “spouted from the wound” (Arrian, Anabasis 6.10.1), something that may indicate a severe lung injury. But Alexander manages to fight on.
Immediately after relating the latter event, Arrian (Anabasis 6.10.2) tells us:
“Many other stories have been written by the historians about the misfortune, and tradition has received them as the first falsifiers told them, and still keeps them alive to this day, nor indeed will it ever cease handing on the falsehoods to others in turn, unless it is checked by this history.”
Basically, Arrian is trying to sell his history as the most accurate, but we have no way to check the veracity of that statement ourselves.
So, how do we know that the “Alexander-Faces-Elephants-Story" is not part of a literary tradition to magnify his exploits rather than a reportage of real events?
Indeed, Marshall seems to not appreciate how often ancient historians saw themselves as in competition with other historians.  Some opted for the most colorful tales to attract an audience, and others marketed themselves as the most accurate. 
In any case, there is no way for us to check the accuracy of Arrian’s own claims  given that he depends on sources whose very accuracy he often questions. He was not an eyewitness to anything. He often has to guess or just go with what seems good to him at the time.
Given those uncertainties and given the recurrence of fighting animals as a heroic theme, saying that Alexander faced elephants in India constitutes “existing knowledge” is naïve, to say the least. It is a reasonable belief, at best.
That is why I am a minimalist. I only accept as worthy of “reasonable belief” those historical claims for which there is sufficient independent textual evidence, preferably contemporary with the events and supported by archaeological data.

As a minimalist, I cannot say that I KNOW that Alexander faced elephants in the battlefields of India. I can only say, very tentatively, that it is reasonable to believe that he did for the following reasons:
-The use of elephants in war is a feasible phenomenon that can be confirmed today because elephants still exist.
-Their use is attested in a wide variety of sources, ranging from Greek to biblical (1 Maccabees 6:34).
-Ancient art shows the use of war elephants.
-India would be a natural place for such elephant warfare due to the prevalence of elephants in that region.
-Since other evidence indicates that Alexander did reach India, then it is likely that his opposition would have used elephants if it were part of their army.
There is also archaeological evidence in the form of medallions (e.g., "The Franks Medallion" in the British Museum) that may depict Alexander’s experience with these elephants. Frank Holt has attempted to make a persuasive case that the person depicted is Alexander.  But artistic depictions, like anything else, are not in themselves proof that an event happened.
                                                                             The Franks Medallion in the British Museum                                                                                                                                          

One must also be cautious because Holt’s methodology has been questioned by Robert Bracey of the British Museum in connection with the authentication of other medallions that some think are forgeries even if the so-called Elephant Medallions are not (See Bracey's comments).
Overall, we have a case where the general claims of Arrian and Plutarch about Alexander facing an army that included elephants are corroborated by a wide range of independent evidence.
To what extent Alexander actually “faced” or directly fought the elephants himself is a different question. I am not sure if Marshall is claiming that Alexander himself faced elephants or just that his soldiers faced them.

Marshall’s claim that “Alexander the Great faced elephants on the battlefield in India,” is NOT EXISTING KNOWLEDGE.
It is, at best, a reasonable belief held on the assumption that the sources are trustworthy.
That belief could be confirmed or disconfirmed by other future evidence, whereas anything called “knowledge” cannot be disconfirmed. If someone claims to know something subsequently proved wrong, then they were simply misusing KNOW, or should have used “BELIEVE” instead of “KNOW.”
More importantly, Alexander’s existence or his battles with an army containing elephants is not at all analogous to skepticism about Jesus’ resurrection.  Here are some differences:
-Alexander’s existence is corroborated in his lifetime by multiple independent witnesses ranging from Egypt to Mesopotamia. 
-Jesus’ existence is corroborated by nothing in his lifetime.
-Arrian and Plutarch say they depend on sources, who have independent attestation to the claim of being eyewitnesses to at least parts of Alexander’s life. There is evidence that Ptolemy, for example, accompanied Alexander.
-We have no independent confirmation that any so-called eyewitnesses mentioned in the NT are any such thing. Luke, for example, speaks of receiving information from eyewitnesses, but he never explicitly names them in Luke 1:1-2.
-Using known phenomena (e.g., war elephants) is not analogous to using unknown phenomena such as resurrecting from the dead or miraculous healings to explain Jesus stories.
-No modern historian accepts as historical any of the supernatural abilities or experiences of Alexander even if they are attested by multiple sources.
Therefore, it is not a case of undue skepticism to believe in at least some of Alexander’s exploits (i.e., those independently corroborated by further evidence) and yet not believe in any or most of Jesus’ exploits.
On the other hand, Christian apologists such as Marshall want us to accept as historical the supernatural activities and experiences of Jesus because they are attested by multiple sources, but presumably not those supernatural events associated with Alexander. 
This reveals an inconsistent historical methodology, and a special pleading for Christian texts that is not accorded to the texts of other religious traditions.  This is clearly religiocentric apologetics, and not scientific history at work. 

It is a simpleton’s approach to history.

1. How do you KNOW that “Alexander the Great faced elephants on the battlefield in India”?
2. Are you saying that you KNOW that Alexander faced elephants just as much as you KNOW that you exist? If not, then why do you use the word KNOW for both?
3. What source do you deem the most trustworthy on this event?
4. How did you determine that that source was trustworthy?
5. If that source depended on an earlier source, how did you determine that the earlier source was trustworthy on this issue?
6. Do you believe that talking serpents led Alexander to the oracle of Zeus-Ammon? Why or why not?
7. Do you believe that Alexander’s father was a god as some of those same Alexander sources claim? If not, why don’t you regard these sources as credible on that issue?

8. Do you believe Alexander healed people, and had prophecies fulfilled about him?
9.  How did you determine that the story of Alexander facing elephants was not part of the heroic literary tradition of semi-divine figures facing animals?
10. What archaeological evidence from the actual battlefield confirms the presence of elephants or Alexander at the Hydaspes battle site?

A. B. Bosworth and E. J. Baynham, eds., Alexander the Great in Fact and Fiction 
               (New York: Oxford University Press, 2000).
P. A. Brunt, Arrian (Loeb Classical Library; Cambridge, MA: Harvard University 
               Press, 1976).
J. R. Hamilton, “The Cavalry Battle at the Hydaspes,” Journal of Hellenic Studies  
              76 (1956): 26-31.
Frank Holt, Alexander the Great Today: In the Interest of Historical Accuracy?”           
             Ancient History Bulletin 13, no. 2 (1999): 111-117.
 --         Alexander the Great and the Mystery of the Elephant Medallions        
            (Berkeley: University of California Press, 2003).
Bernadotte Perrin, Plutarch (London: William Heinemann, 1928).
Joseph Roisman, ed., Brill's Companion to Alexander the Great (Leiden: Brill,