The influence of the love treatise in the lyric poetry of Renaissance Spain has been sufficiently documented and studied with respect to Neoplatonic theory. However, the decisive role of alternative or counter-Neoplatonic theories has not received the same attention. This insufficiency in scholarship appears to exist because treatises expounding such concepts are not nearly as well known as their Neoplatonic counterparts. The thesis examines three works influenced by alternative schools of thought on the nature of love (primarily neo-Aristotelian), whose importance for Spanish literature is belied by the general disregard given them thus far: Flaminio Nobili's Trattato dell'Amore humano, Damasio de Frias's Dialogo de amor, and Eugenio de Salazar's Silva de poesia. Three principal sections comprise the thesis: (i) a general review of secondary sources addressing love theory in the period's prose and verse, with particular attention paid to the influence of the love treatise in the lyric poetry of Renaissance Spain (Chapter 1); (ii) a study of the three primary sources, focusing on the rebuttal of contemporary transcendental notions of love (Chapters 2, 3, and 4); (iii) a transcription, with modernized orthography and punctuation, of poems selected from the Silva de poesia for their conceptual compatibility with (and probable indebtedness to) the two love treatises (Appendix). The study discloses the three works' shared premise regarding the integrality of body and soul, a notion on which is predicated a theory of love that incorporates sexuality and marriage and thereby redresses prominent Neoplatonic conceptions. Significantly, this type of love involving body and spouse is termed 'amor virtuoso' and 'amor verdadero' by, respectively, Frias and Salazar, these designations having usually been reserved to describe spiritual or divine forms of love. In this manner, amor mixtus is redefined and valorized, being regarded not solely as a matter of biological necessity or social obligation (i.e. as means to something else) but as a form of love which is noble in and of itself.