Here again we meet a physicist who wants to fulfil his need of transcendence by using the scientific method only. Most of his life was spent trying to answer philosophical questions by the scientific method. For him, all the answers had to come from 'science'. He was at the forefront of science in his time; trusting his own judgment which took him so far, he had little reasons or incentive to consult someone with very different basic approach to important philosophical questions.
His method, being flawed from the start, he could not satisfy his desire for transcendence, nor could he explain his intuition(or tacit belief) of 'unity' and of 'infinity'.
A very telling passage was an eulogy he wrote for one of his friend, an eulogy that was also read at his own funeral. The eulogy is quoted in full on page 322, at the end of the book.
He says in effect that the finite, being contingent, has to be grounded in the infinite. That the quality of the infinite is convey in the word 'spirit' (wind or breath). This energy (which he would have like to discover with the scientific method, as for him there is no other way to knowledge) infuses all living beings, and without it any organism fall apart.
What is truly alive in the living being is this energy of spirit, and this is never born and never dies.
So that the god he put his faith in was an incomprehensible (so far) energy that always was and ever will be.
Trying to pull himself up by his own boot straps, he naturally could never get off the ground. He did not.