Question: What does Prabhupāda mean by the phrase “impersonal brahman”?
Brahman is consciousness. There are two conditions of consciousness (and all energies): latent or kinetic – otherwise known as “inactive” and “active.”
Active brahman is also called “ātmā” – which means that it has an individuality to it. When consciousness is “activated,” it perceives things, and doing so differentiates it from things and gives it a specific subjective locus. So, active consciousness is brahman as “ātmā.” The root of active consciousness is “param-ātmā.” The branches of active consciousness are “jīva-ātmā.”
So, active consciousness has intrinsic individuality – a sense of personhood: “I am.” Thus personhood is intrinsic in and inseparable from active consciousness.
But there is another type of consciousness, a “latent” or “inactive” consciousness that can only be denoted as brahman, not as ātmā. Since it is latent or inactive it is not conscious of anything (besides itself perhaps) and thus has no sense of differentiation or distinct existence as an individual. So it is called “impersonal brahman” because it is consciousness with no sense of personality or individual existence.
Vraja Kishor [VrajaKishor.com]