Critics of Sāṅkhya often begin with its central dualism between Puruṣa and Prakṛti, noting several logical and metaphysical tensions. If Puruṣa is utterly inactive, changeless consciousness and Prakṛti is unconscious yet dynamic, the precise manner in which their mere proximity yields the rich drama of experience remains obscure. The traditional analogy of a colorless crystal reflecting nearby colors is seen as inadequate to account for the vivid sense of agency, suffering, and bondage that living beings report. This leads to what some call the bondage paradox: if Puruṣa is eternally free and pure, how can it ever truly be bound by Prakṛti at all. The suggestion that Puruṣa is only a “witness” raises further doubts about how moral responsibility and genuine spiritual effort can be grounded.

A second major line of criticism concerns the multiplicity of Puruṣas and the structure of causation. Sāṅkhya infers countless individual Puruṣas from the diversity of embodied experiences, yet rival schools argue that this inference is not compelling and that differences in body, mind, and karma might suffice without multiplying distinct consciousness-principles. The doctrine that effects pre-exist in their causes (satkāryavāda), with all evolutes emerging from Prakṛti, is also challenged for blurring the line between cause and effect and for failing to explain why any process of becoming is needed if the effect is already fully present. The elaborate list of tattvas and the three guṇas as fundamental constituents of Prakṛti are sometimes viewed as conceptually heavy or overly simplistic when set against the complexity of phenomena.

The status of Prakṛti itself raises further questions. As an unconscious yet self-evolving principle, Prakṛti is said to unfold the cosmos “for the sake of” the enjoyment and liberation of Puruṣa, but critics find it difficult to reconcile such apparent purposiveness with the absence of a conscious designer. This difficulty is sharpened by Sāṅkhya’s non-theistic stance, which many theistic traditions regard as unable to account adequately for cosmic order, the distribution of karma, or the scriptural affirmations of a supreme Lord. From the standpoint of Advaita Vedānta, the independent reality granted to both Puruṣa and Prakṛti conflicts with readings of the Upaniṣads that affirm a single non-dual Brahman, while Buddhist critiques question the very notion of a permanent, unchanging consciousness-substratum.

Finally, Sāṅkhya’s account of liberation and its epistemic foundations are also subject to scrutiny. Liberation is described as the realization of the absolute distinction between Puruṣa and Prakṛti, after which Prakṛti is said simply to cease functioning for that particular Puruṣa; yet critics ask why an eternal, independent Prakṛti would stop presenting itself, and whether bondage can be said to have ended if the basic dualism endures. Many of Sāṅkhya’s key postulates—such as the unmanifest Prakṛti and the plurality of Puruṣas—rest heavily on inference, leaving room for alternative explanatory schemes that are equally consistent with experience. Some also regard the path of sharp discriminative knowledge that Sāṅkhya recommends as overly intellectual and insufficiently integrated with devotional or ethical disciplines emphasized in other traditions.