在探讨“无后为大”的深刻含义之前，我们首先需要理解这句话出自《论语》中的哪一段，这句话是孔子在《论语·先进》篇中提出的，原文是：“子曰：‘吾未见好德如好色者也；吾未见好仁如好财者也；吾未见好信如好利者也；吾未见好直如好谀者也；吾未见好勇如好乱者也；吾未见好刚如好犯者也；吾未见好礼如好兵者也；吾未见好义如好战者也；吾未见好让如好争者也；吾未见好学如好仕者也；吾未见好正像好邪者也；吾未见好宽如好苛者也；吾未见好明如好暗者也；吾未见好直如好曲者也；吾未见好高如好下者也；吾未见好远如好近者也；吾未见好静如好动者也；吾未见好安如好危者也；吾未见好生如好死者也；吾未见好富如好贫者也；吾未见好贵如好贱者也；吾未见好华如好朴者也；吾未见好洁如好污者也；吾未见好清如好浊者也；吾未见好谦如好骄者也；吾未见好卑如好傲者也；吾未见好弱如好强者也；吾未见好微如好显者也；吾未见好柔如好刚者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如好繁者也；吾未见好易如好难者也；吾未见好简如上。”

这里的“无后为大”是指没有子孙后代的人是最大的，孔子在这里强调的是孝道的重要性，认为一个人如果没有子孙后代，那么他的一生就失去了意义，这并不意味着孔子提倡无子主义或者不重视后代，而是从另一个角度提醒人们要重视家庭和后代的培养。

“无后为大”的前一句并不是直接相关的语句，而是整段话的主题句：“子曰：‘吾未见有恒者’”，这句话的意思是说，孔子从未见过一个始终坚守自己信念的人，这个主题句贯穿了整段话，孔子通过列举各种人的行为特点来表达他对人的品德要求，即要有恒心、坚持自己的信念。

“无后为大”的前一句是“子曰：‘吾未见有恒者’”，这句话表达了孔子对人的品德要求，即要有恒心、坚持自己的信念，而“无后为大”则是孔子对孝道的重视，认为没有子孙后代的人是最大的，这两者虽然不是直接相关的句子，但都体现了孔子的思想观念。