Some of the most capable of his captains, as we shall see presently, even disagreed as to whether Trafalgar was fought under the memorandum at all.

From the method in which the attack was actually made, so different apparently from the method of the memorandum, some thought Nelson had cast it aside, while others saw that it still applied.

A careful consideration of all that was said and done at the time gives a fairly clear explanation of the divergence of opinion, and it will probably be agreed that those officers who had a real feeling for tactics saw that Nelson was making his attack on what were the essential principles of the memorandum, while some on the other hand who were possessed of less tactical insight did not distinguish between what was essential and what was accidental in Nelson's great conception, and, mistaking the shadow for the substance, believed that he had abandoned his carefully prepared project.
For those who did not entirely grasp Nelson's meaning there is much excuse.

We who are able to follow step by step the progress of tactical thought from the dawn of the sailing period can appreciate without much difficulty the radical revolution which he was setting on foot.

It was a revolution, as we can plainly see, that was tending to bring the long-drawn curve of tactical development round to the point at which the Elizabethans had started.