one ship than it had formerly for a small fleet and sees that these expensive ships are obsolete as soon as they are launched. And the state is just as much upset as Herr Duehring would be over the fact that the controller of the economic force of the ship, the engineer, is a much more important person than the man of pure force, the captain. On the other hand we have no further grounds for annoyance when we see that how as a result of this contest between armour plate and projectile the battle ship has arrived at the point when it is as expensive as it is unfit for fighting and that this contest shows the dialectic law of progress at work in naval warfare according to which militarism like every other historical phenomenon must come to an end as a result of its own development. We can thus see as plain as noonday that it is not true that "the original reason must be sought in pure political force and not in indirect economic force." Quite the contrary. Economic force is the control of the power of the great industry. Political force in naval matters which is dependent upon modern ships of war is by no means "pure force" but is involved in economic force, in the advanced development of metallurgy, in the mastery of historical technique and the possession of rich coal-fields. _IV. Force Theory (Conclusion)._ (Herr Duehring makes an argument which is briefly summarised by Engels as follows and which may be said to involve the notion that the monopolization of land is the cause of human slavery and is the product of force. Engels proceeds): Thesis--The domination of nature by man is the reason of the domination of man by man. Proof--The existence of landlordism on a large scale cannot be carried on anywhere except by means of slavery. Proof of proof--Landlordism on a large scale cannot exist without slavery because the great landlord with his own family without the help of slaves can only cultivate a small piece of his property. Therefore, in order to show that man cannot subdue nature without the subjugation of his fellowman, Herr Duehring transforms "nature" forthwith into "private ownership of large tracts of land" and this indefinite private ownership into the ownership exercised by a great landlord, who naturally cannot cultivate his land without slaves. In the first place the domination of nature and the cultivation of private landed property do not imply the same thing. The domination of nature in industrial affairs is displayed in a manner altogether different from that in agricultural affairs, for these latter are always at the mercy of the climate instead of being supreme over the climate.