The phrase comes from the Roman playwright Titus Maccius Plautus in his comedy Asinaria ("The Comedy of Asses"), written around the late 3rd or early 2nd century BC.

The original Latin is:

Lupus est homo homini, non homo, quom qualis sit non novit.

A literal translation is:

"A man is a wolf to another man, not a man, when he does not know what the other is like."

Or more naturally:

"A person is like a wolf to another person when they are strangers."

How Plautus used it

In Asinaria, the line is spoken by a character expressing caution about dealing with unknown people. The point is not that humans are inherently savage all the time. Rather, Plautus is saying that people often treat strangers as predators or prey because they don't know or trust one another.

The important qualifier is:

"...when he does not know what the other is like."

That clause is often omitted when the phrase is quoted today.

Later interpretations

Centuries later, the English philosopher Thomas Hobbes famously shortened the idea to "Homo homini lupus" ("Man is a wolf to man") and used it in a much broader philosophical sense. For Hobbes, it described the human condition in the "state of nature," where, without government or social order, people would compete violently for survival.

So there is a significant difference:

• Plautus: People can be as dangerous as wolves toward strangers they do not know or trust.
• Hobbes: Humans are naturally in conflict with one another unless restrained by a strong civil authority.

In context, it is practical advice about mistrust between strangers, fitting the play's atmosphere of scams, bargaining, and suspicion. It is not presented as a grand philosophical statement about all human nature, but as an observation that, in business and unfamiliar dealings, people often assume the worst and exploit one another if given the chance.

The popular proverb "Man is a wolf to man" is therefore a simplified version of Plautus's original line, which carries a more specific and conditional meaning than the later Hobbesian interpretation.While it is most famously associated with the 17th-century English philosopher Thomas Hobbes, he actually wasn't the first to say it. The line originates from the Roman playwright Plautus in his 254 BC play Asinaria. Hobbes revived it in his work De Cive (1642) to describe the terrifying, lawless state of nature before the creation of a centralized state.

Whether it's actually true is one of the foundational debates of political philosophy and evolutionary biology. Here is how that debate breaks down:

The Hobbesian View: Absolute Competitive Scarcity

Hobbes argued that without a strong, governing authority (the "Leviathan") to keep everyone in check, humans would inevitably descend into a perpetual war of all against all.

• The Core Argument: Resources are scarce, and because humans are generally equal in their ability to harm one another, fear and self-preservation drive us to strike first. In this state, life is famously "solitary, poor, nasty, brutish, and short."

• The Implication: Human nature is fundamentally egoistic, and "morality" or "justice" can only exist once an overarching power is established to enforce laws.

The Counter-Argument: Mutual Aid and Co-evolution

Many thinkers and biologists argue that the "wolf" metaphor misunderstands both humans and wolves.

• The Biological Reality: Actual wolves are fiercely cooperative pack animals that rely on deep social bonds, shared hunting duties, and altruism to survive. They rarely kill members of their own pack.

• Philosophical Resistance: Thinkers like Jean-Jacques Rousseau argued that humans are not naturally malicious; rather, it is the corrupting structure of modern civilization, property rights, and artificial inequality that make us predatory toward one another.

• The Evolutionary View: As evolutionary theorist Peter Kropotkin argued in Mutual Aid, cooperation, empathy, and community building are just as foundational to human survival—if not more so—than raw competition.

Ultimately, the phrase functions less as a biological fact and more as a diagnostic warning: when social contracts break down and systemic structures isolate individuals, we are entirely capable of turning on one another with terrifying efficiency.