If you are a student or teacher, check your school's (Google Classroom, Moodle, or Microsoft Teams). Many schools purchase digital licenses for Vicens Vives books. Ask your Spanish teacher for the "digital book" (libro digital) code. This grants you access to an official Vicens Vives interactive PDF that is watermark-free and ultra-high resolution.
Let’s be honest: finding this specific file is difficult. Vicens Vives is a commercial publisher (now part of Grupo Anaya). They actively protect their copyright. The physical book costs roughly €10–€12. Consequently, most free PDFs floating around are either:
Google Books often hosts the first 20 pages of Vicens Vives books as a "Preview." While you cannot get the whole book, you can get the introduction and Tratado I in pristine quality. For a study session on the blind man and the stone bull, this is often enough.