This paper investigates Searle’s account of reduction concerning the compatibility between causal reduction and simultaneous ontological irreducibility of consciousness to brain activity. The causal reduction of consciousness – the causal explicability of its features by brain processes and the identity of its causal powers (section 2) – is incompatible with ontological irreducibility (section 3), because the ontological difference between subjective and objective features make the identity of causal powers incomprehensible (section 4). The main problem is that Searle’s theory states and simultaneously denies the identity between consciousness and brain processes (section 5).