What Is Everything Made Of? 萬物是什麼做的？

🔊Heraclitus of Ephesus, writing around 500 BCE, made change itself the key. In John Burnet’s translation: “You cannot step twice into the same rivers; for fresh waters are ever flowing in upon you.” For Heraclitus the world is an ever-living fire, and its stability is like the stability of a flame or a river, a pattern kept up by constant change. He also thought opposites depend on each other. “Cold things become warm, and what is warm cools; what is wet dries, and the parched is moisted.” When Homer prayed that strife might perish, Heraclitus said, he did not see that he was praying for the destruction of the universe. The lesson on the river in the Big Questions shelf takes up his puzzle in detail.

以弗所的赫拉克利特，大約在西元前 500 年寫作，把變化本身當作關鍵。John Burnet 的英譯是：「你不能兩次踏進同樣的河流；因為新的水不斷流向你。」對赫拉克利特來說，世界是一團永恆的活火；它的穩定，就像火焰或河流的穩定：一個由不斷變化所維持的模式。他也認為對立面彼此依存：「冷的變暖，暖的變冷；濕的變乾，乾的變濕。」他說，荷馬祈求紛爭從世上消失的時候，並沒有看到他是在祈求宇宙的毀滅。大哉問書架裡講河流的那一課，會詳細處理他的難題。

🔊Parmenides of Elea, in southern Italy, wrote a poem in which a goddess teaches him “the only two ways of search that can be thought of.” In Burnet’s translation, the first is “that It is, and that it is impossible for it not to be.” The second, that “It is not,” is “a path that none can learn of at all. For thou canst not know what is not—that is impossible—nor utter it; for it is the same thing that can be thought and that can be.” From this he drew startling conclusions. If what is not cannot be, then nothing can come into being, since it would have to come from nothing. Nothing can perish, since it would have to become nothing. There can be no empty space, no motion, and no real plurality. The world of change that our senses show us is an illusion.

義大利南部埃利亞的巴門尼德，寫了一首詩；詩中一位女神教導他「唯一可以設想的兩條探究之路」。Burnet 的英譯是：第一條是「它存在，而且它不可能不存在」。第二條，「它不存在」，是「一條任何人都無法學會的路。因為你無法認識不存在的東西（那是不可能的），也無法說出它；因為能被思想的與能存在的，是同一個東西」。他從這裡推出驚人的結論。如果不存在的東西不能存在，那麼沒有任何東西能夠生成，因為它必須從無中來。沒有任何東西能夠消滅，因為它必須變成無。不可能有空的空間、不可能有運動、不可能有真正的多。我們的感官所顯示的這個變化的世界，是一個幻覺。

🔊This was the first sustained argument in Western philosophy, and it was purely logical. Parmenides did not appeal to observation. He followed a premise to its conclusion and accepted the conclusion even though it contradicted everything we see. His student Zeno defended him with paradoxes, such as Achilles who can never catch the tortoise, designed to show that motion leads to absurdity, and the lesson on Zeno’s paradoxes examines them. Most philosophers since have rejected Parmenides’ conclusion. But they could not simply ignore his argument. If you want change, you have to show where the reasoning goes wrong, or find a way for things to change without anything coming from nothing.

這是西方哲學裡第一個持續展開的論證，而且是純粹邏輯的。巴門尼德沒有訴諸觀察。他把一個前提推到它的結論，並且接受了這個結論，即使它與我們所見的一切相矛盾。他的學生芝諾用悖論來為他辯護，例如阿基里斯永遠追不上烏龜；這些悖論是設計來顯示運動會導致荒謬的；講芝諾悖論的那一課檢查過它們。此後大多數哲學家都拒絕巴門尼德的結論。但他們不能就這樣忽略他的論證。如果你想要變化，你就必須指出這個推理錯在哪裡，或者找到一種方式，讓事物能夠改變，而又沒有任何東西從無中生出。

🔊The next generation took the second route. Empedocles of Acragas, in Sicily, accepted that nothing comes from nothing, but said there are four eternal “roots,” which we call earth, water, air, and fire. In Burnet’s translation: “Hear first the four roots of all things.” They never come into being or perish. They only mix and separate, moved by two forces, Love and Strife. “At one time all the limbs that are the body’s portion are brought together by Love,” and at another they are “severed by cruel Strife.” Anaxagoras of Clazomenae, who brought philosophy to Athens, went further. Every kind of stuff is in everything, in tiny portions: “All things were together, infinite both in number and in smallness.” What sets the mixture moving is Nous, mind, which “is infinite and self-ruled, and is mixed with nothing.”

下一代走了第二條路。西西里阿克拉加斯的恩培多克勒接受「沒有任何東西從無中生出」，卻說有四種永恆的「根源」，也就是我們說的土、水、氣、火。Burnet 的英譯是：「先聽萬物的四種根源。」它們永遠不生成、也不消滅；它們只是混合與分離，由兩種力量推動：愛與爭。「有時，所有屬於身體的肢體被愛聚集在一起」；有時，它們「被殘酷的爭撕裂」。把哲學帶到雅典的克拉佐美尼人阿那克薩哥拉，走得更遠：每一種質料都在每一樣東西裡，以極微小的分量存在：「萬物曾經在一起，在數量上與微小上都是無限的。」使這個混合開始運動的，是 Nous，心靈；它「是無限的、自主的，不與任何東西混合」。

🔊The most lasting answer came from Leucippus and his student Democritus of Abdera. In Ross’s translation, Aristotle reports that they “say that the full and the empty are the elements, calling the one being and the other non-being.” The full is made of atoms, from the Greek for “uncuttable,” tiny solid bodies that differ only in shape, arrangement, and position. The empty is the void in which they move. Atoms never come into being or perish, which satisfies Parmenides, but they move and combine, which rescues change. Everything else, color, taste, warmth, exists only by convention. The atomists were not doing experiments, and their atoms are not the atoms of chemistry. But the idea that the visible world is made of invisible particles in empty space, governed by necessity and not by purpose, would return two thousand years later as the foundation of modern science.

最持久的答案，來自留基伯與他的學生、阿布德拉的德謨克利特。在 Ross 的英譯裡，亞里斯多德記載他們「說充實與虛空是元素，稱前者為存在，後者為非存在」。充實是由原子構成的；「原子」來自希臘文的「不可切割的」：極微小的固體，只在形狀、排列與位置上不同。虛空是它們在其中運動的空間。原子永遠不生成、也不消滅，這滿足了巴門尼德；但它們會運動、會結合，這救回了變化。其他一切，顏色、味道、溫暖，都只是依約定而存在。原子論者並沒有做實驗，他們的原子也不是化學的原子。但「看得見的世界，是由空間中看不見的粒子所構成，受必然性而非目的所支配」這個觀念，在兩千年後會回來，成為現代科學的基礎。