In this direction finality is not sought, for it is apparently unattainable. All that we can say is, in the words of a leading analyst, "sufficient unto the day is the rigor thereof."
Remarks about the translation
E.T.Bell wrote that. I read this cite as is, without surrounding context from the same author. I'm most interested in the part between quotes, because I think I understand the rest.
En este sentido, no se busca el objetivo, ya que es claramente inalcanzable. Todo lo que podemos decir, en las palabras de un destacado analista: "basta a cada dÃa con el rigor del mismo".