 What about Spinoza’s characterization of imaginative ideas as “inadequate” (E2p41d)? Recall that “adequate” ideas are manifestly true ideas fully explained by the mind they help constitute (3.1). So, first, a lack of adequacy is a lack of an intrinsic marker of truth, and hence of certainty that we are dealing with true ideas. Hence when dealing with imaginative ideas we’re not yet able to “distinguish” with certainty “between the true and the false” (E2p402). Of course, we may stumble on the right result (as when we correctly apply a memorized mathematical rule accepted on authority [cf. E2p40s2]). But we cannot yet be sure that our ideas manage to “agree” with, or correspond to, reality.