Mobley on Geissler, 'God and Sea Power: The Influence of Religion on Alfred Thayer Mahan'

Suzanne Geissler
Scott Mobley

Suzanne Geissler. God and Sea Power: The Influence of Religion on Alfred Thayer Mahan. Annapolis: Naval Institute Press, 2015. 280 pp. $39.95 (cloth), ISBN 978-1-61251-843-5.

Reviewed by Scott Mobley (University of Wisconsin-Madison)
Published on H-War (July, 2017)
Commissioned by Margaret Sankey

Most H-War subscribers no doubt will be familiar with Alfred Thayer Mahan’s enduring influence as a strategist, historian, and policy advocate. However, perhaps fewer are aware of Mahan’s strong Christian faith and how that faith influenced his perceptions and ideas. While scholars have long acknowledged Mahan’s religious convictions, many viewed them as a negative force in his life. Others simply dismissed Mahan’s spirituality as unrelated to his larger accomplishments.

Suzanne Geissler challenges these earlier interpretations in her latest book, God and Sea Power: The Influence of Religion on Alfred Thayer Mahan. Geissler rightfully characterizes this biographic work as the “first full-length study of Mahan’s religious faith” (p. 4). The monograph also represents the first detailed examination of Mahan’s life since Robert Seager II’s monumental Alfred Thayer Mahan: The Man and His Letters appeared in 1977. Geissler’s book consists of a short introduction followed by seven chapters. Helpful images depict Mahan’s progression from boyhood to elder statesman and author, his family life, and important locations related to his life story.

Three questions frame Geissler’s study: (1) What was the substance of Mahan’s religious convictions and how did it develop; (2) how did Mahan’s faith influence his naval and geopolitical thinking; and (3) what role did Mahan play in the Episcopal Church?

The opening chapters of God and Sea Power narrate Mahan’s metamorphosis from irreligious (but principled) youth to devout Christian, family man, and naval professional. Central to this transformation was young Lieutenant Commander Mahan’s spiritual journey between 1865 and 1871. Geissler describes these years as a culminating moment in Mahan’s life, marked by a conversion experience through which he embraced spiritual salvation based on “the finished work of Christ” (p. 50). This critical period set the stage for Mahan’s marriage, fatherhood, and subsequent emergence as a historian, strategist, statesman, and Christian activist.

Chapters 5 and 6 offer the most substance with regard to the book’s central questions. Here Geissler gleans from his published works three sets of beliefs stemming from Mahan’s faith--beliefs that profoundly shaped his worldview. First was the notion that God’s purpose guides the course of history and that human choice operates within this larger divine framework. Second, Mahan believed that Christian spirituality offered humankind the closest connection to God--and thus Christian civilization represented the highest form of human society. Finally, Mahan viewed conflict and warfare as the deplorable yet inevitable consequences of original sin. Accordingly, Christian duty demanded just action to suppress wars sparked by human depravity.

Geissler’s research affirms the central role of Christianity in Mahan’s life. Whenever possible he attended three worship services on Sunday. At home, Mahan supervised a familial regimen of daily prayer and Bible study. Throughout adulthood he actively participated in church affairs and outreach projects, most notably the Seamen’s Church Institute in New York City. Following retirement from the navy in 1896, Mahan emerged as a public voice in debates over church governance and policy, the social gospel movement, and other ecclesiastical controversies. While sustaining a prolific output of works on national strategy, policy, and foreign affairs, Mahan also wrote and spoke often to church and secular audiences. During his later years, Mahan published The Harvest Within (1909), a book-length reflection on Christian life.

As an accomplished historian of American religion, Geissler offers fresh perspectives on Mahan’s Christianity and how it shaped his worldview. Exercising a nuanced understanding of Mahan’s High Church Episcopalian faith, Geissler argues that Seager and other scholars misunderstood Mahan’s spiritual beliefs or misinterpreted how religion guided his actions and ideas. Rather than exercising negative or inconsequential influences, Geissler claims that Mahan’s religious convictions beneficially shaped his personal and professional actions. She supports her arguments convincingly with extensive primary evidence from manuscript collections and publications, including thorough analyses of Mahan’s published writings and unpublished papers.

For example, during the immediate post-Civil War years Mahan suffered through a seemingly unhappy period characterized by Seager as severe psychological depression. By comparison, Geissler identifies Mahan’s postwar tribulations as a spiritual struggle, not a mental breakdown. Mustering evidence from Mahan’s correspondence, his personal diary, and other documents, she effectively demonstrates how Mahan’s distress culminated in his conversion experience of 1871. Gessler links the “professional conversion” through which Mahan later generated his famous sea power theories to the spiritual conversion he experienced as a young man (p. 91).

In addition to introducing a new interpretive framework for understanding Mahan, Geissler challenges previous scholarship of his life on technical grounds: insufficient evidence, jumbled facts, interpretive errors, and personal bias. However, while much of this critique is valid some readers may find these frequent technical discussions tedious and distracting. In one passage, Geissler shows how Seager conflated source documents, misread evidence, and presented faulty conclusions to mischaracterize the reasons Mahan’s daughters never married. For her part, Geissler concludes that the evidence provides no definitive answer as to why the two young women remained single for life, despite their father’s earnest advice on seeking husbands.

God and Sea Power offers important new insights for readers wishing to develop a balanced understanding of Alfred Thayer Mahan. Geissler’s analysis of Mahan’s religion and its influence is essential reading for scholars and others interested in the life and global influence of this prominent historical actor. Students of military history, diplomatic history, and US empire will find Gessler’s work especially helpful and informative.

Printable Version:

Citation: Scott Mobley. Review of Geissler, Suzanne, God and Sea Power: The Influence of Religion on Alfred Thayer Mahan. H-War, H-Net Reviews. July, 2017.

This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.