Contrary to its traditional definition as an argument that “seems true but is actually false,” speciousness arises when reasoning is based on species-level elements (selective instances, isolated moments, or specific cases) while ignoring the genetic-level structure of the full causal or logical argument itself.

The Feckless Popular Definition

A variety of popular dictionaries define the term specious as follows:

• Cambridge: “Seeming to be right or true, but really wrong or false.”
• Merriam-Webster: “Having a false look of truth or genuineness.”
• Collins: “Apparently correct or true, but actually wrong or false.”
• Oxford English (requires a subscription): 18 meanings listed, four of which are obsolete.

The fundamental flaw in all these definitions is that they are specious in themselves, committing the fallacy of petitio principii (begging the question). The standard definition—”seeming to be right or true, but really wrong or false”—is entirely circular, assuming its own conclusion as its premise. Rather than serving as a precise tool for logical classification, it functions as a rhetorical bludgeon, reducing the term to little more than a baseless assertion of dismissal.

Labeling an argument as specious in this manner is what the ethical skeptic calls a nulla infantis argument, or ‘baby’s no’—a feckless rebuttal that lacks both analytical rigor and explanatory power. This definition fails to establish a meaningful distinction or provide a method for identifying why an argument is flawed. It conflates genetic reasoning (the logical calculus of an argument) with species-level reasoning (isolated examples or outliers), offering no insight beyond a decorative nuh-uhh. Its use in this manner is both demeaning and pretentious at the same time.

In this article, we will not merely ad hoc dismiss the standard social definitions of the term; rather, we will seek to demonstrate precisely why these definitions are inherently flawed in terms of their philosophical practicality.

Philosophical Backdrop

Pierre de Fermat used the term specious arithmetic to describe arithmetical reasoning that may or may not be valid in a stand-alone context, but is ultimately misleading or incorrect in its broader set of application.¹ However, in mathematics, soundness and correctness are one and the same—a formula, calculation, or segment thereof is genetically both sound and correct or it is not.

In other words, if a segment of a valid mathematical construct is contextually consistent, it is inherently genetically correct by definition and, therefore, cannot be specious. Conversely, anything that is incorrect is necessarily specious by rule. This is not a matter of congruence in definition but rather a case of coincident necessity in the particular case of maths.

However, this strict a fortiori bifurcation does not apply to most aspects of reasoning or debate, where ambiguity, context, and interpretation play a role. As a result, the term has been extended beyond mathematics and, in the process, reductively misdefined.

In Fermat’s time, specious did not carry the modern pejorative connotation of outright falsehood. Instead, it meant something closer to ‘plausible but potentially misleading’—a reasoning trap that could ensnare even its own architect. A conditional warning flag for when a magician might be deceived by his own anecdotal trick or species of argument.

Apparently, as our culture grows more obtuse, our language follows suit—both by reducing the richness of available terms (lexical paring) and by eroding once-nuanced words into mindless blunt dismissals (term hollowing). Both of these linguistic degradations were central plot elements in the cinematic production Idiocracy.

Moreover, E.R. Clay in the late 19th century, and later William James in The Principles of Psychology (1890), defined the specious present as:

The practically cognized present. A saddle-back in time, with a breadth of its own, upon which we sit perched and from which we gaze across two directions into time, bearing no inherent rightness or wrongness.

As such, any given specious moment can serve to be deceiving to the individual who perceives it, may not be deceiving at all, or may even constitute a sound observation or meta-deception (see my case example below). Not because the moment is ‘wrong, appearing to be right’ as the dictionaries above define it, but rather because a specious moment, when taken as a standalone element, may be singularly differentiated from the broader chain of logic and causality. It may even contain a kernel of truth and still be specious—merely a species of moment in time relating both soundness as well as falsehood. A reality that would frustrate the likes of Fermat and Vieta.

The art of research lies in choosing the probative-yet-imperfect over the correct-yet-misleading.

Beware of Sudden Thefts

I was traveling in New York City one evening and boarded a subway train on my way to meet a client for dinner. As I settled into an empty car, my eyes happened to land on a sign across from me that read: “Beware of Sudden Thefts.”

Lowering my head to glance at my phone, I processed the message, and a moment later, the absurdity of it struck me—What an odd and almost comically alarmist warning to post in a subway car. I looked up again, and sure enough, the sign still read: “Beware of Sudden Thefts.”

Then, right before my eyes, the text—which had been machine-carved into the plastic sign—dissolved into a matrix of white dots, flickered, and reassembled into the phrase: “Beware of Sudden Stops.”

I sat there stunned for a moment, questioning what I had for lunch—or my very sanity itself.

At the next station, a group of youths entered the car—some hoodied, hands in pockets, postures slouched, each one subtly mirroring the others. One of them cast a quick glance toward another and gave a barely perceptible nod in my direction, assuming I wouldn’t notice. But I caught the gesture in the reflection of the railcar’s window.

Heeding the warning from my strange specious moment, I slipped out of the car just as the bell sounded and the doors slid shut.

In this specious moment of meta-deception, my perception of the sign was both alluring and incorrect—but that alone did not make it specious. The key distinction offered here is that my perception was also sound. Soundness and correctness are two distinct logical categorizations. An argument can be specious without being entirely wrong—because it may still follow a sound logical calculus, even if its premise or conclusion is flawed in context.

My experience was specious not because it was technically incorrect, but because it represented a single, isolated instance (species) within a broader chain of logical calculus of the day’s events (genetics). The moment, taken by itself, was indeed false—yet, it still proved to be sound in its genetic logical calculus.

Such is an example of the philosophical disconnect within material empiricism when treated as the sole means of divining broader reality—reducing its supposed authority to a specious and ignorance-inducing approach to our existence.

The fabric of our reality carries intent, and unwise is he who ignores its ever-present whisper.

A New, More Functional Definition

Taking this perspective into consideration, a specious argument is one that selectively leverages a species of example (i.e., individual case examples, moments in time, or outlier observations) as the essence of its contention. It is not that such an argument is abjectly wrong, but rather that it constitutes a weaker position of argument.

Specious (adj.)

An argument or contention which is plausible but potentially misleading. An argument which attempts to selectively confirm or refute a broader genetic principle by means of an individual or species of case example, inclusion or exclusion, moment in time, or outlier observation—that is extracted or isolated from the broader genetic context under consideration.

A specious argument is not inherently wrong. It may appear correct within its limited frame of reference while misleading when viewed in full scope, or conversely be wrong in its limited context, but sound in a broader scheme of context. A form of category error, where a person mistakes an instance for the essence or leverages a species of observation as the genetic argument itself.

Speciousness arises when an argument relies on species-level reasoning (selective instances, isolated moments, or specific cases) while ignoring the genetic-level structure (the full causal or logical sequence).

This context of employment is much more effective in philosophical or logical terms.

Examples:

• debunking of case examples or observations (as distinct from ‘falsification’)
• ‘connecting the dots’ of linear inductive inference
• anecdotes to the presence (data) or absence (not data)
• appeals to an ignoratio elenchi or ill-framed question
• appeals to p-value or confidence interval in evaluating a poorly defined or observed domain
• appeals to authority
• appeals to popularity
• cherry picking

By this redefinition, the term specious remains true to its mathematical heritage while becoming a meaningful and functional tool for sincere deliberation and discourse in philosophy and debate.

The Ethical Skeptic, “What is a Specious Argument?”; The Ethical Skeptic, WordPress, 15 Feb 2025; Web, https://theethicalskeptic.com/2025/02/15/what-is-a-specious-argument/