Sentence:  The way to be happy is to live according to nature, in obedience to that universal and unalterable law with which every heart is originally impressed; which is not written on it by precept, but engraven by destiny; not instilled by education, but infused at our <WSD>nativity</WSD>. 
Meaning of the word marked with <WSD> tags:  Someone's birth; the place, time and circumstances of a birth. (from 14th c.)