EXHIBIT 23.5 CONSENT OF PRICEWATERHOUSECOOPERS We hereby consent to the use in this Registration Statement of Quintus Corporation on Form S-4 of our report dated February 8, 1999, except as to Notes 4 and 11, for which the date is March 31, 1999, relating to the financial statements of Acuity Corp. appearing in this proxy statement/prospectus, which is part of this Registration Statement. We also consent to the reference to us under the heading "Experts" in such proxy statement/prospectus. /s/ PricewaterhouseCoopers LLP Austin, Texas March 24, 2000 II-10