Beckwith’s daring but compelling book on Pyrrho’s Encounter with Early Buddhism argues for quite a few propositions that are contentious, to say the least, among scholars. It is especially the attempt to boldly argue for these more daring claims–substantiated by a rich knowledge of the sources and a skillful interpretation, combined with an excellent linguistic expertise–that makes Beckwith’s work an original, fascinating, and intriguing read even for those who do not agree with all of the claims in the book. Beckwith wants to dispense with the temptation to interpret what he calls ‘Early Buddhism’ in the light of later ’Normative Buddhism’, claiming that ‘Early Buddhism’ was, in fact, distinctively different. He argues that the most accurate picture of early Buddhist thought can be found in contemporary Greek Sources about India (see p. 54, and his analysis of Megasthenes’ account, pp. 71-94), in the Inscriptions of King 210 Acta Via Serica, Vol. 5, No. 1, June 2020 Devānāmpriya Priyadarśi (pp. 125-135), and to a degree in the early layers of Taoist writings (pp. 117-124). Beckwith’s methodological assumption is to always trust earlier sources more than later ones, and that “theories must accord with the data” (p. x; see also p. 68). This leads him to disregard the oral tradition and transmission of Buddhist teachings and therefore to favor foreign sources more than native ones (see p. 68, FN 23, where he states that Indian sources are usually up to a millennium younger, never were properly edited, and “consist largely of fantasy”). This preference might not sit well with all scholars of Buddhism or with many Indologists, and one might argue for the faithfulness at least of parts of the oral transmission, rather than brushing them off. Nevertheless, Beckwith can counter that his assumptions follow from his principle to only accept written testimony that is dated close to the debates in question in order to avoid relying upon pious anachronistic rewritings of history (p. 68; and against an example of such a rewriting see p. 104). 
Some of the central claims in regard to the Early Buddhism of Beckwith’s books are, first, that the historical Buddha Gautama was likely a foreigner himself, namely a Scythian sage who introduced novel ‘foreign teachings’. This argument is based on an interpretation of the term ‘Śākyamuni’, as referring to the Scythians, as opposed to the traditional understanding of that title as referring to a local Nepalese Śākya clan (pp. 5-6). Second, Beckwith argues that Early Brahmanism and Early Buddhism should be interpreted as two opposed reactions to the introduction of Zoroastrianism to the region (p. 9). Third, he argues that the term Śramaṇas in all ancient texts up until at least late antiquity (and therefore also in the Greek sources) only refers to Buddhists, and not to ‘ascetics’ in general (pp. 69, 94-100, 102). This allows him to take what is said about the Śramaṇas as valuable information regarding what especially Early ‘prenormative’ Buddhism looked like. A fascinating and, of course, controversial claim is the meticulously etymological-linguistically argued proposition that Lao-Tzu, or LaoDan, the founder of Daoism, is in fact Buddha Guatama himself (pp. 117-123). In that way, the teaching of the Dharma and the Dao are not only closely connected, but in origin are the same teaching (p. 122). 
Next to all these claims, Beckwith wants to understand Pyrrho’s teaching as originating from Pyrrho’s encounter with Early Buddhism while he was traveling to India in the convey of Alexander the Great. These claims give the book its title, even though the book, as just seen, covers much more than this topic.
Beckwith argues that Pyrrho’s teaching “as a system” is unprecedented in Greek philosophy and that it constitutes something like a philosophical revolution (p. 17-19, and for the Greek tradition, Appendix A). Beckwith reconstructs Pyrrho’s teaching from Timon’s report in the ‘Aristocles passage’ in Eusebius, and parallels it closely with.
Some of the central claims in regard to the Early Buddhism of Beckwith’s books are, first, that the historical Buddha Gautama was likely a foreigner himself, namely a Scythian sage who introduced novel ‘foreign teachings’. This argument is based on an interpretation of the term ‘Śākyamuni’, as referring to the Scythians, as opposed to the traditional understanding of that title as referring to a local Nepalese Śākya clan (pp. 5-6). Second, Beckwith argues that Early Brahmanism and Early Buddhism should be interpreted as two opposed reactions to the introduction of Zoroastrianism to the region (p. 9). Third, he argues that the term Śramaṇas in all ancient texts up until at least late antiquity (and therefore also in the Greek sources) only refers to Buddhists, and not to ‘ascetics’ in general (pp. 69, 94-100, 102). This allows him to take what is said about the Śramaṇas as valuable information regarding what especially Early ‘prenormative’ Buddhism looked like. A fascinating and, of course, controversial claim is the meticulously etymological-linguistically argued proposition that Lao-Tzu, or LaoDan, the founder of Daoism, is in fact Buddha Guatama himself (pp. 117-123). In that way, the teaching of the Dharma and the Dao are not only closely connected, but in origin are the same teaching (p. 122). 
In his chapter on David Hume’s skepticism that was inspired by Pyrrhonian thought, Beckwith hints at his own understanding of the relationship between philosophy and skepticism (see Chapter 4). Beckwith portrays the skeptical attitude as an antidote to any form of dogmatic philosophy and to the search for absolute truth, and thus sides with the Pyrrhonian line of thought. One might reasonably disagree with Beckwith’s high estimation of the philosophical importance of the Pyrrhonian skepsis and its place in the history of ideas – which unfortunately is not something that can be argued for in the limited scope of a short book review. It may suffice to point out that an opposing reading of skepticism is possible – not as an insurmountable challenge (see Beckwith’s claim that today the Humean problem ‘is generally considered ‘unsolvable’, p. 139) to the ultimately fruitless search of ‘dogmatic’ philosophy, but, contrarily, as an unavoidable passage step for any responsible philosophical claim to certainty. It is striking to notice that the most far-reaching claims of ‘unhypothetical’ (Plato), ‘certain’ (Descartes), and ‘absolute’ (Hegel) knowledge are developed by philosophers as a direct response to radical skeptical challenges. One has to think of Socrates’ struggle with the Sophists, Descartes’ method of ‘absolute doubt’, and Hegel’s quite interesting self-interpretation of his philosophy as a ‘fulfilling and perfection’ (Vollendung) of skepticism. Such a reading would also allow us to place Pyrrho– against Beckwith’s claims in the Appendix A– closer into the tradition of Greek philosophy (via the Democritean skeptical tradition). 
Be that as it may, the enormous importance of Pyrrhonian skepticism for the Hellenistic world, and the extraordinary high estimation of Pyrrho in his time and after his death point indeed to quite a remarkable individual. Maybe, with Beckwith, an even more remarkable Northern-Indian (or Scythian?) sage inspired him to find a way from the merely academic debates of Hellenistic philosophy to a philosophy of life that enlightened and inspired his contemporaries.
Beckwith’s book is, all in all, certainly worth a close examination and study. He does not provoke in order to provoke, but substantiates his most daring assumptions with expertise and well-argued scholarship. Therefore, even if controversial, his ideas will continue to inspire further debate and hopefully more fruitful research. The many exciting claims in this book make it a must-read for everyone studying the interaction of what we today call ‘East and West’ at the beginnings of Buddhism.