何謂如來？ What is Tathagata?

如來，是佛的十大稱號的第一個稱號。	Tathagata, which means "thus having come" is the first one of Buddha's ten characteristics.
如來，顧名思義，就是「好像來了」，以量子力學的觀點而言，就是「處於來與不來的疊加狀態」。	Tathagata, as implied by the name "thus having come", means "as having come". In the aspect of quantum mechanics, it means "in a state being the superposition of having come and having not come".
《金剛經》云：「如來者，無所從來，亦無所去，故名如來。」來或不來、去或不去， 只是波函數的崩塌狀態，無法描述事物的全貌，它們有所偏狹，而不究竟圓滿，故如來非是。	Diamond Sutra says that, "Tathagata is neither having come from anywhere, nor having gone to anywhere, so it is called Tathagata." Having come, having not come, having gone or having not gone is only a collapsed state of a wavefunction. By only one of them, we cannot describe a full view of a thing. They are partial, but perfect, so Tathagata means none of them.
《金剛經》又云：「如來者，即諸法如義。」諸法如義，就是「各種性質都依循佛法」，而佛法是究竟圓滿的，它涵蓋了各種可能性。因此，如來就是「處於各種性質都處於各種可能性的疊加狀態的狀態」。	Diamond Sutra also says that, "Tathagata means in which all ways are such." Here, "all ways are such" means "all properties follow Buddhism". Since Buddhism is perfect, it covers all possibilities. Therefore, Tathagata means "in a state in which all properties are in a state being the superposition of all possibilities".
如來之定義，以符號表示如次： ∃T⇔(∃P⇔∃∪Pi∀i)∀P 其中，T為如來，P為特定性質，Pi為特定狀態，i為特定狀態編號。	The definition of Tathagata is symbolically expressed as follows: ∃T⇔(∃P⇔∃∪Pi∀i)∀P Wherein T means Tathagata, P means a property, Pi means a state, and i means a state number.