We have many different kinds of intelligence, which may be debatable:
Sometimes intelligence stands in the way of understanding Source Energy. It wants to dissect, analyze, and prove itself right. It is looking for all the flaws so it can dominate them and protect itself. Very intelligent people can torture themselves endlessly over everything that could go wrong, from cosmic explosions to atomic meltdowns and entropy in interpersonal relationships . Intellectually understanding all the possible consequences of every action can lead to paralysis and incapacitating anxiety.
Spiritual enlightenment is a state of inner peace. It is not the mind racing around trying to solve every problem in the world or even every personal issue. And there are many paths to this peace. The intellect is not usually one of them. Yet the Stoics and other philosophers are able to use logic to arrive at a sense of resignation to what is, combined with a zest for being alive. However, in general, it is not the head, but the heart that opens the gates to enlightenment.