Belonging to the real nature of a thing, essential; possessing substance, having practical importance. In law, substantive pertains to provisions of law dealing with rights and duties, as distinguished from procedural provisions, which dictate procedures in court.
Note: The accent falls on the first syllable of this word, as in SUBstuhntive, not subSTANtive.
You can’t remember sex. You can remember the fact of it, and recall the setting, and even the details, but the sex of the sex cannot be remembered, the substantive truth of it, it is by nature self-erasing, you can remember its anatomy and be left with a judgment as to the degree of your liking of it, but whatever it is as a splurge of being, as a loss, as a charge of the conviction of love stopping your heart like your execution, there is no memory of it in the brain, only the deduction that it happened and that time passed, leaving you with a silhouette that you want to fill in again.
—E. L. Doctorow Billy Bathgate (1989)