This paper attempts to reconstruct the scientific investigations that led Isaac b. Judah Abravanel (1437-1508) to endorse a unique opinion concerning corporeal form. These investigations began when Abravanel was a young man in Lisbon. As part of his formal education, Abravanel learned that there was a consensus among medieval thinkers about the independent ontological existence of corporeal form. He also became aware of different opinions regarding the nature of this form and its act. At that time as well as later in his career, he learned about objections to these prevalent opinions and even raised objections of his own. Ultimately he dismissed these opinions. He presented this conclusion in a comprehensive discussion of the notion of corporeal form, written less than two years before his death. There, he also advanced a minority opinion, rejecting the concept of a form that has an independent ontological existence, intermediate between this matter and substantial forms. He argues that the prime matter is endowed with indeterminate dimensions through an act of an aspect of substantial form.