Introduction

The psychological characterization of historical figures presents persistent methodological challenges. As a result, much scholarship has relied either on impressionistic biographical inference1–3 or on retrospective diagnostic speculation,4–6 both of which risk anachronism, overinterpretation, and category error.7–9 In contrast, the present protocol builds on established approaches in intellectual history, microhistory, narrative psychology, and the sociology of knowledge that infer dispositional orientations through the systematic analysis of patterned archival texts.10–13

Within the history of health movements, this problem is particularly salient. Founders of reform-oriented systems, such as Sigmund Freud and Andrew Taylor Still, frequently operated at the intersection of scientific ambition, cultural dissent, and personal conviction, and their intellectual temperaments have been shown to shape both the conceptual structures and institutional trajectories of the movements they developed.14,15 Understanding how such dispositions are expressed and constrained within historical contexts therefore remains an important, but methodologically sensitive, task.

Daniel David Palmer (1845–1913), founder of chiropractic, provides a suitable case for such an inquiry. He left an extensive corpus of writings, correspondence, and public statements spanning several decades, and his life has been the subject of sustained historical documentation and debate. Assessments of his character have been sharply polarized, ranging from portrayals of exceptional intellectual originality14,16 to dismissive characterizations that questioned his credibility and competence within dominant medical and cultural discourse.17,18 Within this contested historiography, Palmer’s writings and biographical record reveal not only technical claims about health and disease, but also consistent rhetorical patterns concerning authority, dissent, discovery, and legitimacy.19–24 Despite the richness of this material, however, his dispositional orientations have rarely been examined in a systematic and methodologically explicit manner.

Cultural context is integral to the analysis undertaken in this study. Palmer’s career unfolded within late 19th-century American settings shaped by frontier individualism, populist distrust of professional authority, metaphysical healing movements, and contested processes of professionalization. These conditions informed both the substantive content and the rhetorical form of his writings.

The present study protocol does not seek to replace historical biography or to uncover a “true” personality behind the texts. Rather, it addresses a narrower and more defensible question: what recurring dispositional orientations are expressed across Palmer’s archival writings, and how are these patterns shaped by their cultural and intellectual contexts, as well as by salient biographical events? The protocol contributes by making the process of dispositional inference explicit and reproducible.

In response to ongoing debates in historical personality research, the study employs a single primary analytic approach—the systematic analysis of patterned archival texts to infer dispositional orientations, conducted in a non-diagnostic and explicitly constrained manner—supplemented by an independent handwriting-based interpretation included solely as an exploratory, non-confirmatory comparison. This component is neither evidentiary nor diagnostic, but serves to illustrate how different interpretive traditions engage distinct material traces.

By emphasizing methodological restraint and transparency in the analysis of patterned archival texts, the protocol offers a defensible framework for historical dispositional inference that may be adapted to other figures with sufficient archival material. All inferences are framed as probabilistic and historically situated, and the approach explicitly avoids claims regarding psychopathology, stable personality structure, or predictive traits.

Methods

This study sets out a protocol for examining a corpus of texts authored by Daniel David Palmer, together with relevant biographical materials, to identify consistent patterns in how he presented himself, argued his ideas, and positioned himself in relation to authority, opposition, originality, and credibility over time. It does not attempt to diagnose Palmer or to reconstruct personality in a clinical sense. These recurring patterns—referred to here as dispositional orientations—are inferred only when they recur across multiple writings and contexts, rather than from isolated instances. Cultural and historical context is used to distinguish expressions that are normative or strategic for the period from those that reflect more stable patterns of self-positioning. All inferences are framed as probabilistic and historically situated. An independent handwriting-based interpretation is included solely as an exploratory, non-confirmatory comparison.

Analytic Framework

This study employs a structured protocol to infer dispositional orientations from archival materials through systematic textual analysis informed by psychological concepts. The protocol is designed to identify recurring orientations expressed across authored texts and biographical materials, while remaining explicitly constrained, non-diagnostic, and historically situated. Dispositional orientations are inferred probabilistically from patterned expressions rather than from isolated quotations, emblematic episodes, or retrospective psychological labeling.

The analytic approach integrates methods from intellectual history, microhistory, narrative psychology, and the sociology of knowledge. Texts are treated as historically situated forms of action and self-presentation, and inference is constrained by attention to genre, audience, institutional context, and cultural norms. No claims are made regarding psychopathology, stable personality structure, or predictive traits.

Materials and Sources

Primary materials consist of archival texts authored by Daniel David Palmer, including published writings, editorials, instructional materials, and autobiographical statements, as well as contemporaneous biographical records and correspondence where available. These materials are treated as complementary forms of archival evidence: authored texts are analyzed as discursive behavior, while biographical materials provide contextual and situational constraints on interpretation.

Secondary historical sources—including scholarly histories of chiropractic, studies of nineteenth-century American medical pluralism, and analyses of professionalization in health movements—are used to situate Palmer’s writings within their intellectual, cultural, and institutional contexts.

Expressive Domains and Dispositional Inference

In this protocol, the analytic terms authority, dissent, discovery, and legitimacy function as expressive domains rather than traits. They designate recurring thematic arenas in which dispositional orientations are manifested across texts.

  • Authority refers to how the subject positions themselves in relation to institutions, experts, professional hierarchies, and established knowledge systems.

  • Dissent concerns how opposition, conflict, and resistance are framed, justified, and sustained.

  • Discovery captures how claims of originality, insight, revelation, or privileged epistemic access are articulated.

  • Legitimacy refers to how credibility, entitlement, recognition, and moral or epistemic standing are asserted or defended.

Across these domains, the analysis infers recurring dispositional orientations, such as oppositional versus conciliatory, autonomous versus deferential, charismatic versus procedural, and absolutist versus provisional. These orientations constitute the dispositional level of analysis and are understood as patterned tendencies of expression and positioning, not as discrete personality traits or psychological diagnoses.

Cultural and Historical Context as Interpretive Constraint

Cultural and historical context is treated as an integral component of structured dispositional inference, serving to constrain interpretation rather than to expand psychological claims. Contextual analysis is used to distinguish dispositional orientations from expressions that are normative, strategic, or genre-specific within a given historical setting.

Palmer’s career unfolded within late 19th-century American contexts shaped by frontier individualism, populist distrust of professional authority, metaphysical healing movements, and contested processes of medical professionalization. These conditions are treated as informing both the substantive content and rhetorical form of his writings. Accordingly, contextual norms, institutional pressures, and available discursive repertoires are incorporated as interpretive constraints when assessing whether a recurring pattern reflects a dispositional orientation or a situational response.

Analytic Procedure

Texts are to be examined iteratively to identify recurring patterns of language use, self-positioning, agency attribution, conflict framing, and epistemic stance across genres and contexts. Dispositional orientations are to be inferred only when patterns recur across distinct texts and situations, rather than appearing in isolated or situationally specific instances.

Interpretation is to proceed conservatively, with attention to counterevidence, absences, and variation across contexts. All inferences are framed as provisional and probabilistic, reflecting the fragmentary and mediated nature of historical evidence.

Exploratory Comparative Analysis: Handwriting (Graphological) Interpretation

As an explicitly exploratory and non-confirmatory component, the study includes an independent graphological assessment of selected handwritten materials produced by Daniel David Palmer. Graphology emerged in late 19th- and early 20th-century Europe as a characterological interpretive practice grounded in expressive analysis rather than experimental psychology. Although historically influential in certain intellectual and cultural contexts, it has since been widely criticized and displaced within scientific psychology. In the present study, graphology is therefore not treated as a scientific method or a source of psychological evidence, but as a historically situated interpretive tradition included solely for exploratory comparison.

The assessment draws on the French graphological tradition associated with the work of Jules Crépieux-Jamin, whose holistic approach to handwriting interpretation conceptualizes handwriting as an expressive system structured around form, movement, pressure, spacing, and rhythm. Within this tradition, handwriting is approached as a patterned mode of expression rather than as a diagnostic indicator, and interpretation proceeds from global features toward more specific configurations.

The inclusion of this tradition reflects scholarly interest in historically influential approaches to character interpretation that have been employed in European intellectual and cultural contexts.25–29 In the present protocol, the graphological assessment is treated as a descriptive interpretive perspective derived from a distinct material trace, not as evidence, validation, or psychological assessment. Its role is limited to comparative reflection on how different interpretive traditions characterize the same historical individual when working from different forms of archival material.

Epistemic Limits

Throughout the analysis, explicit attention is given to interpretive limits. All inferences are historically situated and probabilistic in nature. No claims are made regarding psychopathology, stable personality structure, or predictive traits. The protocol is intended to clarify how dispositional characterizations are generated and constrained by method, rather than to resolve debates about the subject’s “true” personality.

Results (Anticipated Outcomes)

The primary outcome of this study will be the systematic mapping of recurring dispositional patterns across archival textual evidence, rather than the identification of definitive personality traits. The analysis is expected to identify consistencies and tensions in Palmer’s modes of self-representation, authority attribution, engagement with opposition, and epistemic stance across genres of writing.

Rather than yielding novel biographical facts, the analysis is expected to contribute analytic structure to features of Palmer’s temperament that are already visible in his writings but are typically discussed impressionistically. By applying explicit interpretive criteria and analytic frameworks, the protocol aims to clarify how frequently, and in what contexts, certain orientations—such as assertiveness, resistance to external authority, confidence in personal insight, or persistence in the face of criticism—appear, and how these orientations vary across time and communicative purpose. The added value of this approach lies in transforming qualitative impressions into systematically documented patterns that can be examined, compared, and debated.

The exploratory handwriting analysis is expected to produce an independently generated descriptive profile of expressive tendencies as interpreted by a trained graphologist, without claims of validation or causal inference. Any points of convergence or divergence between the text-derived dispositional patterns and the handwriting-based observations will be reported descriptively and treated as comparative observations rather than confirmatory evidence. Discrepancies are treated as equally informative as similarities, highlighting the limits of inference across modalities.

When interpreted within their historical context, the findings are expected to illustrate how Palmer’s dispositional orientations interacted with the social, professional, and intellectual conditions of late nineteenth-century America. The results will not be framed as explanations of chiropractic’s success or failure, but as contextual factors shaping Palmer’s rhetorical strategies, institutional boundary-making, and responses to criticism.

Finally, the results are intended to function as a demonstration of methodological feasibility rather than empirical validation. The study is expected to show that cautious, transparent, and non-diagnostic dispositional inference from archival texts is possible when interpretive limits are explicitly stated. This outcome supports the protocol’s broader contribution: offering a replicable framework for historically grounded dispositional inference that may be applied, with appropriate restraint, to other historical figures with sufficient textual documentation.

Discussion

The purpose of this study is to examine whether dispositional orientations can be inferred from archival textual evidence in a transparent, cautious, and methodologically constrained manner, without seeking to alter existing historical interpretations or to advance novel psychological claims about Daniel David Palmer’s character. The anticipated contribution of this work lies primarily in how Palmer’s writings are analyzed rather than in uncovering previously unknown features of his temperament. Whereas prior scholarship has relied largely on close reading, selective quotation, and narrative synthesis, the present protocol introduces an explicit analytic structure that renders interpretive steps visible, contestable, and reproducible.

By requiring cross-textual recurrence across genres and contexts, the protocol is expected to clarify how consistently certain orientations—such as autonomous versus deferential positioning, oppositional versus conciliatory framing, or absolutist versus provisional epistemic stance—are expressed in Palmer’s writings. These orientations are not presented as latent psychological traits, nor as explanatory mechanisms for chiropractic’s emergence, but as historically situated patterns of self-positioning and rhetorical practice. The value of the approach lies in distinguishing between isolated or situational expressions and more durable orientations that persist across time, audience, and communicative purpose.

Historical contextualization is essential to this interpretive process. Dispositional orientations inferred from Palmer’s texts cannot be meaningfully interpreted outside the social and professional conditions of late nineteenth-century America, including medical pluralism, populist dissent, frontier individualism, and contested authority in healthcare. Rather than attributing Palmer’s positions to personality alone, the analysis situates individual orientations as interacting with—and constrained by—these broader cultural and institutional forces. This framing avoids reductionism while acknowledging that individual dispositions can shape how historical actors respond to shared structural conditions.

The exploratory handwriting-based interpretation is deliberately positioned as a comparative adjunct rather than a source of evidentiary confirmation. Given the longstanding controversy surrounding graphology, its role in this protocol is limited to generating an independently derived descriptive perspective that can be placed alongside text-based inferences. Convergence is not treated as validation, and divergence is not treated as error; instead, comparison serves to illustrate the epistemic limits of inference across different material traces. This restrained use reflects current scholarly consensus that graphology cannot support diagnostic or predictive claims, while still allowing it to function as an object of methodological reflection.

More broadly, this study contributes to ongoing debates concerning whether and how psychological concepts can be responsibly applied in historical research. The protocol explicitly rejects retrospective diagnosis and avoids the application of modern personality categories to historical figures. Instead, it adopts a dispositional framework focused on tendencies, orientations, and patterned expressions, all framed probabilistically and within historical constraint. In this respect, the approach aligns with established practices in intellectual history, political psychology, and psychohistorical scholarship, where personality-related constructs are employed descriptively rather than clinically.

Finally, the significance of this work extends beyond the case of Palmer. By articulating clear analytic steps, acknowledging interpretive bias, and delineating epistemic limits, the protocol offers a model for cautious dispositional inference that may be adapted to other historical figures with sufficiently rich archival records. Whether particular interpretations persuade or not, their value lies in making interpretive assumptions explicit rather than implicit. In this sense, the study contributes not a definitive portrait of Palmer’s personality, but a disciplined framework for examining how individual dispositions may be discussed—critically, transparently, and without overreach—within historical scholarship.

Scholarly and Educational Significance

1. Professional Identity and Historical Self-Reflection

Discussions of chiropractic’s origins often oscillate between celebratory narratives and dismissive critiques. By examining Palmer’s writings through a structured and explicitly constrained analytic framework, this study encourages a more nuanced engagement with the profession’s formative period. Rather than reinforcing hagiographic or adversarial accounts, the approach foregrounds complexity and historical contingency, supporting a mature professional identity capable of critical self-reflection without either idealization or repudiation.

2. Implications for Educational Contexts

Chiropractic education commonly includes historical and philosophical components, yet these are often presented descriptively rather than analytically. The present study offers a model for incorporating historical figures into curricula in a way that emphasizes interpretation, context, and methodological caution. Palmer’s writings may thus serve as case material for examining how personal orientation, cultural context, and professional ambition interact in the formation of new disciplines—without requiring acceptance of any particular psychological interpretation.

3. Reflection on Disposition and Professional Practice

Although this study makes no claims about contemporary clinical behavior, it highlights the relevance of dispositional factors in professional life more generally. By demonstrating how modes of authority, conviction, and rhetorical positioning are expressed in Palmer’s texts, the analysis underscores that professional theories are often inseparable from the individuals who articulate them. This observation may encourage reflective awareness of how personal orientations shape professional reasoning and communication.

4. Bridging Historical Analysis and Contemporary Discourse

Current debates within chiropractic concerning evidence, philosophy, and public legitimacy frequently invoke Palmer’s legacy. By situating his writings within their historical and cultural context, this study supports a more informed and critical use of historical reference in contemporary discourse, distinguishing historical influence from present-day normative claims.

5. Contribution to Interdisciplinary Scholarship

Beyond chiropractic, this study offers a cautious model for interdisciplinary inquiry at the intersection of history and psychology. By avoiding diagnostic claims, treating controversial methods as exploratory, and foregrounding interpretive limits, the protocol demonstrates how dispositional questions may be pursued in historical research without epistemic overreach. Its principal contribution is methodological: showing how personality-related inquiry can be conducted responsibly, transparently, and critically within archival scholarship.

Ethical Considerations

This study is based on historical and archival materials and does not involve direct interaction with living individuals as research subjects. The core analysis consists of historically constrained interpretation of texts authored by Daniel David Palmer. An independent graphological assessment of selected handwritten materials is included as an exploratory and non-confirmatory comparative component. As such, the study is not anticipated to constitute human subjects research under U.S. federal regulations (45 CFR 46.102). Where required by institutional policy, the project may be submitted for administrative or exempt determination.

The protocol explicitly avoids retrospective diagnosis, pathologizing, or deterministic psychological judgments of historical figures. Any dispositional orientations discussed are framed as descriptive, probabilistic, and historically situated patterns inferred from archival evidence rather than as traits, diagnoses, or causal explanations.

Ethical responsibility in historical scholarship also requires balanced representation. Selective celebration or undue criticism risks distorting understanding of both the historical figure and the profession associated with them. This study seeks to acknowledge Daniel David Palmer’s contributions and limitations without resorting to hagiography or dismissal, emphasizing complexity, contextual constraint, and interpretive humility.

Because interpretations of Palmer’s writings may resonate within contemporary chiropractic discourse, findings are presented in a manner intended to encourage scholarly reflection rather than professional defensiveness. Interpretations are offered as historically situated analyses, not as normative statements about contemporary practice or professional legitimacy.

Finally, ethical scholarship requires explicit acknowledgment of methodological limits. Dispositional inferences drawn from archival texts and handwriting cannot establish definitive traits or causal explanations. All interpretations are therefore framed as provisional, context-dependent, and open to critique, in keeping with standards of scholarly integrity.

Author Positionality

I approach this study as a historian of chiropractic with training in archival research and historiography, with specific scholarly engagement in the archival writings, biographical record, and historiography of Daniel David Palmer and early chiropractic history.30–33 I have no prior professional or formal training in the specific interdisciplinary methodology outlined in this protocol. The core analysis is conducted through historically constrained interpretation of archival texts. An independent graphological assessment of selected handwritten materials is included as an explicitly exploratory and non-confirmatory comparative component. The protocol does not require specialized clinical or technical expertise beyond historically grounded textual interpretation.

Interpretive decisions related to historical context, source selection, and narrative framing are informed by established historiographical methods. Throughout the study, reflexivity is emphasized, and my interpretive role is explicitly distinguished from any external interpretive traditions.

Use of Artificial Intelligence Tools

Artificial intelligence–assisted tools were used during manuscript preparation solely for language editing, structural organization, and clarity of expression. All methodological design decisions, theoretical framing, and interpretive conclusions were developed by me.

I take full responsibility for the content, structure, and scholarly claims of the manuscript.

Conclusion

Limitations

This study protocol is subject to several limitations inherent to historical, interpretive, and interdisciplinary research. First, the availability and completeness of archival materials constrain the analytic scope. Not all of Daniel David Palmer’s writings, correspondence, or manuscripts have survived, and some of those that remain represent selective snapshots rather than a comprehensive record of lived experience.

Second, the interpretive nature of psychologically informed content analysis necessarily involves judgment. Although the protocol incorporates explicit interpretive criteria, historical constraint, and reflexive documentation, the analyses cannot achieve objectivity in a positivist sense. Interpretations remain contingent on theoretical assumptions and analytic choices that must be open to critique.

Third, handwriting analysis occupies a contested position within psychological scholarship. For this reason, graphological observations in this protocol are explicitly framed as exploratory and comparative, not evidentiary or confirmatory. No claims of validation, prediction, or diagnostic inference are made, and the inclusion of graphology is intended to examine methodological convergence and divergence rather than to establish psychological truth.

Finally, any attempt to infer dispositional orientations from historical texts is necessarily partial. Archival writings reflect rhetorical intent, audience, genre, and context as much as personal disposition. Accordingly, all inferences generated by this protocol are probabilistic, historically situated, and limited to patterns of expression rather than underlying psychological states.

Implications

Despite these limitations, the protocol has several implications for historical scholarship and professional reflection. For historians of chiropractic, it offers a structured approach to examining how individual dispositions may intersect with institutional formation, rhetorical strategy, and boundary-making, without reducing historical development to personality alone.

For scholars in psychology and the humanities, the study illustrates how psychologically informed textual analysis can be applied cautiously to historical figures when epistemic limits are clearly articulated. The protocol contributes a methodological framework rather than substantive psychological claims, demonstrating how interdisciplinary inquiry can proceed without retrospective diagnosis or theoretical overreach.

Within educational contexts, the study supports a more critical engagement with foundational figures. Rather than treating Palmer’s writings as doctrinal authority or dismissing them as idiosyncratic, the approach encourages examination of how historical actors navigated uncertainty, conflict, and innovation within their cultural milieu.

This study protocol proposes a transparent and restrained framework for examining dispositional orientations in historical figures through archival texts. By integrating psychologically informed textual analysis with historical contextualization—and by incorporating handwriting analysis solely as an exploratory comparison—the protocol emphasizes methodological clarity over evidentiary certainty.

Applied to the case of Daniel David Palmer, the framework does not seek to reconstruct personality, diagnose character, or explain the emergence of chiropractic through individual psychology. Instead, it demonstrates how patterns of expression, authority, and self-positioning can be systematically examined within their historical context.

More broadly, the protocol contributes to ongoing discussions about the responsible use of psychological concepts in historical research. Its primary value lies not in the conclusions it generates, but in the discipline it imposes on interpretation—making assumptions explicit, limits visible, and claims open to scholarly debate.