＂阿爾克西拉烏斯（希臘語：Ἀρκεσίλαος；公元前316/5年至前241/0年）是一位古希臘的希臘化時期哲學家。他是學術懷疑論的創始人，且創立了不同階段被稱為第二學院、中學院或新學院的柏拉圖學院，這是學院轉向哲學懷疑主義的時期。＂
"Arcesilaus (/ˌɑːrsɛsɪˈleɪ.əs/; Greek: Ἀρκεσίλαος; 316/5–241/0 BC) was a Greek Hellenistic philosopher. He was the founder of Academic Skepticism and what is variously called the Second or Middle or New Academy – the phase of the Platonic Academy in which it embraced philosophical skepticism.
Arcesilaus succeeded Crates of Athens as the sixth scholarch of the academy around 264 BC. He did not preserve his thoughts in writing, so his opinions can only be gleaned second-hand from what is preserved by later writers.
In Athens Arcesilaus interacted with the Pyrrhonist philosopher, Timon of Phlius,whose philosophy appears to have influenced Arcesilaus to become the first Academic to adopt a position of philosophical skepticism, that is, he doubted the ability of the senses to discover truth about the world, although he may have continued to believe in the existence of truth itself. This brought in the skeptical phase of the academy. His chief opponent was his contemporary, Zeno of Citium, the founder of Stoicism, whose dogma of katalepsis (i.e., that reality could be comprehended with certainty) Arcesilaus denied.
Arcesilaus was born in Pitane in Aeolis. His early education was provided by Autolycus the mathematician, with whom he migrated to Sardis. Afterwards, he studied rhetoric in Athens. He then studied philosophy, becoming a disciple first of Theophrastus and afterwards of Crantor. He also attended the school of Pyrrho, whose philosophy he maintained, except in name. He subsequently became intimate with Polemo and Crates of Athens, who made Arcesilaus his successor as scholarch (head) of the Platonic Academy.
Diogenes Laërtius says that, like his successor Lacydes, Arcesilaus died of excessive drinking, but the testimony of others (e.g. Cleanthes, who said that he lived a dutiful life) and his own precepts discredit the story.He is known to have been much respected by the Athenians.
Arcesilaus committed nothing to writing. His opinions were imperfectly known to his contemporaries, and can now only be gathered from the statements of later writers. This makes his philosophy difficult to evaluate and partly inconsistent. This led scholars to see his skepticism in several ways. Some see his philosophy as completely negative or destructive of all philosophical views. Others regard him as taking the position that nothing can be known on the basis of his philosophical arguments. Others claimed he held no positive views on any philosophical topic, including the possibility of knowledge.
Arcesilaus' contemporary, Aristo of Chios, described Arcesilaus as being: "Plato the head of him, Pyrrho the tail, midway Diodorus" meaning that Arcesilaus presented himself as a Platonist, the substance of what he taught was the dialectics of Diodorus, but his actual philosophy was that of Pyrrhonism. Eusebius, probably quoting Aristocles of Messene, reported that Arcesilaus studied in Pyrrho's school and adhered, except in name, to Pyrrhonism.Numenius of Apamea said "Arcesilaus accompanied Pyrrho. He remained Pyrrhonist in his rejection of everything, except in name. At least the Pyrrhonists Mnaseas, Philomelos and Timon call him a Pyrrhonist, just as they were themselves, because he too rejected the true, the false, and the persuasive." Sextus Empiricus said that Arcesilaus' philosophy appeared essentially the same as Pyrrhonism, but granted that this might have been superficial.
On the one hand, Arcesilaus professed to be no innovator, but a reviver of the dogma-free dialectic that had characterized the academy under Plato. Thus he is said to have restored the doctrines of Plato in an uncorrupted form. On the other hand, according to Cicero, he summed up his opinions in the formula, "that he knew nothing, not even his own ignorance." There are two ways of reconciling the difficulty: either we may suppose him to have thrown out such aphorisms as an exercise for his pupils, as Sextus Empiricus, who calls him a "skeptic", would have us believe; or he may have really doubted the esoteric meaning of Plato, and have supposed himself to have been stripping his works of the figments of the Dogmatists, while he was in fact taking from them all certain principles.
Cicero attributes the following argument to Arcesilaus:
(i) it is rash and shameful to assent to something false or unknown, but since
(ii) nothing can be known (and obviously we shouldn't do what is rash and shameful),
(iii) we should suspend judgment about everything
Zeno of Citium and the other Stoics were the chief opponents of Arcesilaus. He attacked their dogma of katalêptikê phantasia (i.e., a convincing conception) as understood to be a mean between episteme (knowledge) and doxa (opinion). He argued that this mean could not exist. It involved a contradiction in terms, as the very idea of phantasia implied the possibility of false as well as true conceptions of the same object. As such, it was merely the interpolation of a name."
阿爾克西拉烏斯（希臘語：Ἀρκεσίλαος；公元前316/5年至前241/0年）是一位古希臘的希臘化時期哲學家。他是學術懷疑論的創始人，且創立了不同階段被稱為第二學院、中學院或新學院的柏拉圖學院，這是學院轉向哲學懷疑主義的時期。
阿爾克西拉烏斯在公元前264年左右繼承了雅典的克拉底斯，成為學院的第六任校長。他沒有將自己的思想以文字形式保存下來，因此他的看法只能從後來作家保存的資料中間接瞭解。
在雅典，阿爾克西拉烏斯與畢浪主義哲學家、來自斐利烏斯的提孟進行了互動，提孟的哲學似乎影響了阿爾克西拉烏斯成為第一位採取哲學懷疑主義立場的學術派，也就是他懷疑感官發現世界真理的能力，雖然他可能仍然相信真理本身的存在。這引入了學院的懷疑主義階段。他的主要對手是他的同時代人，斯多葛學派的創始人，澤諾，澤諾堅持認為現實可以確定地被理解，阿爾克西拉烏斯否認了這一教條。
阿爾克西拉烏斯出生於愛奧利斯的皮坦。他的早期教育是由數學家奧托呂克斯提供的，阿爾克西拉烏斯隨他遷移到薩爾迪斯。之後，他在雅典學習修辭學。接著，他研究哲學，先成為了泰奧弗拉斯托斯的門徒，然後又成為了克蘭特的學生。他還參加了畢浪的學校，他維持了畢浪的哲學，除了名稱之外。後來他與波萊摩和雅典的克拉底斯建立了密切關係，克拉底斯讓阿爾克西拉烏斯成為他的繼任者，擔任柏拉圖學院的校長。
狄奧尼修斯·拉爾提烏斯說，就像他的繼任者拉策代斯一樣，阿爾克西拉烏斯因過度飲酒而死，但其他人（例如克萊恩西斯，他說阿爾克西拉烏斯過著謹慎的生活）的證詞和他自己的準則駁斥了這個故事。眾所周知，他在雅典人中享有很高的尊敬。
阿爾克西拉烏斯並未留下任何文字記載。他的觀點在他的同代人中知之甚少，現在只能從後來的作家的記述中了解。這使得評價他的哲學變得困難且部分不一致。這導致學者對他的懷疑主義有多種看法。有些人認為他的哲學完全是否定或破壞了所有的哲學觀點。其他人則認為他認為根據他的哲學論證無法知曉任何事物。還有人聲稱他對任何哲學話題都沒有積極的觀點，包括知識的可能性。
阿爾克西拉烏斯的同代人阿里斯多德描述他是：“柏拉圖在他之前，皮浪在他之後，狄奧多魯斯在中間”，這意味著阿爾克西拉烏斯自認為是柏拉圖主義者，他所教授的實質內容是狄奧多魯斯的辯證法，但他的實際哲學卻是皮浪主義。尤西比烏斯可能引用了亞里斯多德·梅森尼的話，報告說阿爾克西拉烏斯曾在皮浪的學派中學習，除了名稱上的不同，他遵從了皮浪主義。阿帕梅亞的紐米尼烏斯說：“阿爾克西拉烏斯和皮浪同行。他在拒絕一切方面保持了皮浪主義者的立場，除了名稱之外。至少皮浪主義者姆納西亞斯、菲羅梅洛斯和提蒙稱他為皮浪主義者，就像他們自己一樣，因為他也拒絕了真實、虛假和有說服力的東西。”塞克斯都斯·埃米匹里科斯說，阿爾克西拉烏斯的哲學在本質上看起來與皮浪主義相同，但也承認這可能只是表面現象。
一方面，阿爾克西拉烏斯宣稱自己不是一個創新者，而是柏拉圖時代學院所特有的無教條辯證法的復興者。因此，他被認為是以純淨形式恢復了柏拉圖的教義。另一方面，根據西塞羅的說法，他總結了自己的觀點為一個公式：“他一無所知，甚至連自己的無知也不知道。”解決這個難題有兩種方式：一種是我們可以假設他發表這樣的格言是為了他的學生進行練習，正如西塞斯·埃米匹里科斯所說的，他稱其為“懷疑論者”；或者他可能真的對柏拉圖的深奧含義感到懷疑，並認為自己正在剝離他的作品中教條派的虛假，而實際上他從中提取了某些原則。
西塞羅將以下論點歸因於阿爾克西拉烏斯：
(i) 盲目地或對未知的事情表示同意是魯莽和可恥的，但由於
(ii) 沒有什麼是可知的（顯然我們不應該做魯莽和可恥的事），
(iii) 我們應該對一切都懸置判斷。
西提亞的瑟洛和其他斯多葛派是阿爾克西拉烏斯的主要對手。他批評了他們的可信觀念（即，一個令人信服的概念），認為它是知識和意見之間的一個平衡點。他主張這個平衡點是不存在的。這涉及了一個名詞上的矛盾，因為觀念這個概念本身就意味著對同一對象的真實和虛假觀念的可能性。