What does it mean to feel passionately for the subject one teaches? What does such a passion entail for those involved in the teaching-learning situation? This study focuses on the teacher's passion for their subject. Nine scholarly texts were reviewed, which allowed for four distinct notions of passion to be discerned: i.e., romantic, friendly, erotic, and divine love. Findings showed also combinations of these notions as well as ontological variations. Inductively created themes revealed that the foundations of these different notions of passion ranged from love of the Truth and the Good to a calling from the subject, and that the character of these notions ranged from them being about intellectual and emotional allure to being about their being disclosed and brought to fulfilment. It also revealed what the different notions of love entailed for the teacher, the student, and the subject itself: for the teacher-from a demand to seek the good in the subject to a requirement to perceive the subject as a voice, the subject in turn making their life meaningful; for the student-from becoming part of the community of "we who love subject X" to a "homecoming of self-hood"; and for the subject itself-from beginning to reveal itself to holding teachers and students accountable. The usefulness of the findings for teacher education and research on teacher-student relations is discussed.