Proto-Endocrinological Theories of Masculinity/Femininity (1490-1904)

Area of Science:

• History of Endocrinology
• Reproductive Biology
• History of Medicine

Background:

• Explores proto-endocrinological concepts of testicular influence on secondary sexual characteristics from the mid-seventeenth century.
• Traces the evolution of thought from Galen's "On Semen" (1490) through early modern medical theories.

Observation:

• Early theories focused on testicular "ferment" or semen resorption for secondary sexual characteristics.
• Physicians debated the pathways and medium of testicular influences on physical, mental, and behavioral traits.
• Concepts shifted from Galen's "heat and strength" to blood-borne "virility," "seminal ferment," and "seminal recrement."

Findings:

• The "recrementitious secretion" theory, involving semen reabsorption, was a prominent early concept.
• These ideas preceded the modern understanding of internal secretion and the hormone era.
• By the late eighteenth century, significant controversy surrounded these concepts and their proposed anatomical pathways.

Implications:

• Reconstructs the historical development of ideas leading to modern endocrinology.
• Highlights the intellectual journey from ancient concepts to the cusp of the hormone era.
• Demonstrates the long-standing scientific inquiry into the biological basis of sex characteristics.