Pursuant to Rule 102, the purpose of the Illinois Rules of Evidence is to promote “the end that the truth may be ascertained and proceedings justly determined.” In that regard, foundation for a witness’ knowledge about an issue is required to be shown in order for the witness’ testimony to be admitted.The Illinois Supreme Court in Wills v. Foster adopted the most radical version of the collateral source rule discussed in this space last week and on Aug. 19, 2020. That allows plaintiffs to recover for the total amount …