But that seemed utterly unattainable.

So it seemed to himself at least.

He could not imagine, for instance, that he would sometime leave off thinking, get up and simply go there....

Even his late experiment (i.e.his visit with the object of a final survey of the place) was simply an attempt at an experiment, far from being the real thing, as though one should say "come, let us go and try it--why dream about it!"-- and at once he had broken down and had run away cursing, in a frenzy with himself.
Meanwhile it would seem, as regards the moral question, that his analysis was complete; his casuistry had become keen as a razor, and he could not find rational objections in himself.

But in the last resort he simply ceased to believe in himself, and doggedly, slavishly sought arguments in all directions, fumbling for them, as though someone were forcing and drawing him to it.
At first--long before indeed--he had been much occupied with one question; why almost all crimes are so badly concealed and so easily detected, and why almost all criminals leave such obvious traces?
He had come gradually to many different and curious conclusions, and in his opinion the chief reason lay not so much in the material impossibility of concealing the crime, as in the criminal himself.