Subjugated knowledge and subaltern knowledge (or more precisely, knowledge produced by/associated with the subaltern) are two related but distinct concepts in critical theory. They both deal with forms of knowing that are marginalized or oppressed by dominant power structures — yet they come from different intellectual traditions, have different emphases, and lead to quite different political implications.

Here is a clear side-by-side comparison:

Aspect	Subjugated knowledges (Foucault)	Subaltern knowledge / voice (Spivak / Postcolonial theory)
Main thinker	Michel Foucault (especially Power/Knowledge, 1976–77 lectures)	Gayatri Chakravorty Spivak (most famously "Can the Subaltern Speak?", 1988) + Subaltern Studies group
Core meaning	Knowledges that have been disqualified, buried, delegitimized or rendered subordinate by dominant scientific/institutional discourses	Knowledge/consciousness/voice of the most radically subordinated groups (especially in colonial contexts) that have been structurally silenced
Who possesses it?	Broad and heterogeneous: psychiatric patients, prisoners, folk traditions, local practitioners, "naïve" knowledges, indigenous memories, etc.	Very specific: the most oppressed of the oppressed — illiterate peasantry, tribal groups, lowest urban proletariat, especially colonized women in extreme subalternity
Nature of exclusion	Hierarchical disqualification ("insufficiently scientific", backward, local, insufficiently elaborated)	Epistemic violence — colonial discourse overwrites / erases / makes impossible the very conditions for self-representation
Can it speak / be recovered?	Yes — Foucault sees tactical political value in resurrecting these knowledges through genealogy (the "insurrection of subjugated knowledges")	Deeply pessimistic — "the subaltern cannot speak" in any authentic, unmediated way within dominant (colonial/academic) discourse
Political aim	Tactical / disruptive — use buried knowledges as weapons to challenge the power-effects of official "Truth"	Critique / ethical warning — show the impossibility of transparent representation; question whether even well-meaning intellectuals can avoid re-colonizing the subaltern
Optimism level	Relatively optimistic (resistance is possible through strategic reactivation)	Radically skeptical (representation usually ends up serving the intellectual/First World subject)
Typical field of application	Western institutions (madness, prison, sexuality, medicine) + broader power/knowledge nexus	Colonial & postcolonial situations (especially India), Third World, gender + class + caste intersections
Famous quote	"an insurrection of subjugated knowledges"	"Can the subaltern speak?" → answer is essentially no (in any non-distorted way)
Relation to representation	Interested in using these knowledges politically without necessarily romanticizing them	Deep suspicion of any claim to represent or speak for the subaltern (including by radical Western intellectuals like Foucault & Deleuze)

Quick summary of the key tension

• Foucault: "Let's dig up and mobilize these disqualified knowledges to fight power where it currently operates."
• Spivak (criticizing Foucault among others): "Even when you try to let the most radically subaltern speak, you (the intellectual) usually end up reinforcing your own position as the subject who knows/represents. The truly subaltern voice is not recoverable in any pure form — the system that could record it has already destroyed the conditions for its existence."

In practice many contemporary postcolonial, decolonial and indigenous scholars try to work between these two positions — taking Foucault's tactical energy while remaining very aware of Spivak's devastating critique of representation.

So in short:

• Subjugated knowledges → broad, tactical, recoverable-for-resistance
• Subaltern knowledge/voice → narrowly extreme, structurally erased, almost impossible to authentically hear/represent.

grok