If one has provided a little more than is necessary, it is much easier to leave out something later than it is to add more, if one has not provided enough; and one's natural indolence then acts on the side of safety, since it tends to persuade one not to leave off too much; whereas in the opposite case, it tends to assure him that it is not really necessary to take the trouble to provide what it might be hard to get.
_The Estimate of the Situation .-- In no field of strategical work is an accurate estimate of the situation more clearly necessary than when it is to form the basis for the precise calculations of logistics_.

General strategical plans require a vividness of imagination and a boldness of conception that find no field for exercise in logistics; and tactics requires a quickness of decision and a forcefulness of execution that neither strategy nor logistics need; but neither strategy nor tactics calls for the mathematical exactness that logistics must have, or be of no avail.

Yet there will be no use in working out the mathematically correct means to produce certain result, if the real nature of the desired result is underrated; there will be no use in working out laboriously how many ships and tons of coal and oil are needed, if the estimate of the situation, to meet which those ships and coal and oil are needed, is inadequate.
The first step, therefore, in providing for the expansion of the navy for war, is to estimate the situation correctly.

The greatest difficulty in doing this arises from a species of moral cowardice, which tempts a man to underestimate its dangers, and therefore the means required to meet them.

_Probably no single cause of defeat in war has been so pregnant with disaster as this failure to make a sufficiently grave estimate of the situation_.