His inmost mind, a region difficult to penetrate under the best of circumstances

From the Guns of August by Barbara Tuchman.

“Echoes of the secret meeting of the C.I.D. angered the Cabinet members who had been left out and who belonged to the sternly pacifist wing of the party. Henry Wilson learned that he was regarded as the villain of the proceedings and that they are “calling for my head.” At this time began the split in the Cabinet which was to be so critical in the ultimate days of decision. The government maintained the disingenuous position that the military “conversations” were, in Haldane’s words, “just the natural and informal outcome of our close friendship with France.” Natural outcome they might be; informal they were not. As Lord Esher with a certain realism said to the Prime Minister, the plans worked out jointly by the General Staffs have “certainly committed us to fight, whether the Cabinet likes it or not.”

There is no record what Asquith replied or what, in his inmost mind, a region difficult to penetrate under the best of circumstances, he thought on this crucial question.