These days, he is reading a biology text lent to him by one of his two sons, a college biology major.
It was the Jijoan biology text he had written with Uthen.
He had read nearly every biology text in Biblos and figured he should at least understand the vocabulary.
The biology texts they developed covered evolutionary theory, which was by this time overwhelmingly accepted as biology's central organizing principle.
In 1985, the organization reviewed major biology texts and found 50 percent of them did an inadequate job of teaching evolution.
"We felt something had to be done," recalled Marla Perkel, a former auxiliary police officer who records biology texts for the blind.
Today most biology texts cover evolution, but in specific chapters that can be conveniently ignored by teachers under threat.
But it is a scientific fact, as any basic biology text will confirm, that life does begin at conception.
"When the bond is broken, energy is released" is the most common statement in every biology text book out there.
"I saw her in the hall today, fifth period," Mark was saying as he gathered up a biology text and a geometry notebook.