Definition
Secrets of state are governmental information whose disclosure would injure the public interest, national security, or the proper functioning of executive branch affairs. The concept operates as a privilege — a shield against compelled disclosure in judicial proceedings — held by the sovereign rather than by any private party.
At common law, the doctrine recognized that certain documents and communications touching on military operations, diplomatic affairs, intelligence activities, or sensitive executive deliberations stood outside the ordinary reach of courts and litigants. A court could not compel a minister or department head to produce such materials simply because they were relevant to pending litigation. The public interest in secrecy was deemed to outweigh the private interest in disclosure.
In modern American law, this doctrine survives and has been formalized as the state secrets privilege — an evidentiary rule rooted in federal common law by which the executive branch may resist discovery or use of information whose disclosure would harm national security or foreign relations.
Common Confusion
SECRETS OF STATE vs. EXECUTIVE PRIVILEGE vs. DELIBERATIVE PROCESS PRIVILEGE: These three concepts are related but distinct. Secrets of state (the state secrets privilege) protects specific information whose disclosure would damage national security or foreign affairs; it is absolute in character once properly invoked. Executive privilege is broader and covers presidential communications and advice regardless of security implications. The deliberative process privilege protects internal agency deliberations from disclosure to promote candid policymaking but is qualified — it can be overcome by a sufficient showing of need. Researchers working in historical sources will find these distinctions blurry; earlier writers often used "secrets of state" loosely to cover what modern doctrine separates into distinct privileges.
Core Elements
For the privilege to attach in its modern form, courts and commentators generally require:
1. Government assertion. The privilege must be formally claimed by the head of the executive department with control over the information, after personal consideration. It cannot be invoked by a private party or by counsel alone.
2. Specificity of harm. The government must identify, with reasonable particularity, why disclosure would damage national security, foreign relations, or public service — not merely that the information is sensitive or embarrassing.
3. Judicial gatekeeping (limited). A court may examine the claim, but the scope of that review is narrow. Where the privilege is properly invoked on security grounds, courts have historically deferred heavily to the executive's judgment.
4. Effect on litigation. A successful assertion may result in exclusion of specific evidence or, where the privileged material is so central that the case cannot proceed fairly without it, dismissal of the action entirely.
Why It Matters in Research
The primary research trap is terminological drift. Bouvier and other historical sources use "secrets of state" as an umbrella phrase that encompasses what modern doctrine has disaggregated into the state secrets privilege, executive privilege, and official information privilege. A researcher reading a nineteenth-century treatise should not assume the author is describing any one of these modern categories precisely.
Bouvier's formulation is historically important for a specific structural point: the question of whether privileged documents must be produced is determined not by the judge but by the head of the department holding them. This principle — deference to the executive on the threshold question — persisted into twentieth-century American case law, though courts have since asserted a modest gatekeeping role.
Researchers should also distinguish the evidentiary doctrine (privilege against compelled disclosure in litigation) from the broader political and constitutional concept of state secrecy (classification systems, national security law, FOIA exemptions). Historical dictionaries address only the evidentiary dimension; the statutory and administrative apparatus for managing classified information is a twentieth-century development entirely absent from those sources.
The connection to trade secrets is purely nominal. Despite shared vocabulary, secrets of state and trade secrets are unrelated doctrines with different purposes, different holders, and different legal frameworks. The overlap in Law Mind's corpus between employment law materials on trade secrets and this entry reflects only the word "secrets," not any substantive legal relationship.
For corpus navigation: the Civil Procedure & Evidence Encyclopedia entry is the primary analytical home for this doctrine. Researchers approaching the topic through administrative or national security law will need sources outside the traditional common law dictionary shelf.
Historical Dictionary Support
Bouvier's entry is brief but structurally precise on two points that matter. First, it establishes that a judge at nisi prius — a trial court — lacks power to compel production of documents connected with affairs of state when production would injure the public service. Second, and more significant, Bouvier draws a procedural line: the determination of injury to public service belongs to the head of the department, not to the court. This places the privilege outside ordinary judicial control at the threshold stage.
Bouvier also notes a qualifying circumstance — the rule shifts when the department head does not personally attend at trial — though the surviving excerpt is truncated and the full rule as stated by Bouvier cannot be reconstructed from the available text. Researchers should consult a complete edition for that qualification.
What historical dictionaries do not address: the modern state secrets privilege's absolute character once properly invoked, the possibility that a court may examine documents in camera, the procedural consequences when privileged evidence is central to a plaintiff's claim, or the tension between the doctrine and due process in national security litigation. All of this is post-Bouvier development.
Jurisdictional Note
The state secrets privilege is a federal common law doctrine and applies in federal court proceedings. State courts have analogous official information privileges, but their scope and the degree of judicial deference to the executive vary considerably. Researchers working in state court materials should not assume federal doctrine applies.
Encyclopedia Cross-Reference
Government Privileges — State Secrets, Official Information, and Deliberative Process (The Law Mind Civil Procedure & Evidence Encyclopedia)