Without a universal human nature, confidence in strangers is groundless.

Evidence

In that respect, to rely upon the unity and the will of the party is exactly like my reckoning that the train will run to time or that the tram will not be derailed. But I cannot count upon men whom I do not know, I cannot base my confidence upon human goodness or upon man’s interest in the good of society, seeing that man is free and that there is no human nature which I can take as foundational. I do not know where the Russian revolution will lead. — Jean-Paul Sartre, Existentialism Is a Humanism, 17

Categorization

• DEFINE: This contrasts reliance on known, controllable commitments (a party one enrolls in) with ungrounded faith in humanity, clarifying what existentialist engagement can and cannot rest on.
• DEEPTHINKING: The move from ‘no human nature’ to ‘therefore I may trust my immediate comrades but never unknown men’ is a dense argument that repays sitting with; it defines the epistemic boundaries of socialist solidarity.
• XREF: connects to: Humans lack any predefined nature and create themselves through choices — Sarah Bakewell, At the Existentialist Café: Freedom,…, 26

Related

• Humans lack any predefined nature and create themselves through choices (similarity 0.79)

Broader Connections

• Humans lack any predefined nature and create themselves through choices #expands (0.85) — Sarah Bakewell, At the Existentialist Café, 26