If it is true that...

The organization of proletarians into a class is continually upset by competition between the workers themselves

Then it must be true that...

Collisions between classes further the development of the proletariat

If it is true that...

The organization of proletarians into a class is continually upset by competition between the workers themselves

and

Collisions between classes further the development of the proletariat

Then it must be true that...

The bourgeoisie finds itself in a constant battle with various groups including foreign bourgeoisie

If it is true that...

The organization of proletarians into a class is continually upset by competition between the workers themselves

and

Collisions between classes further the development of the proletariat

Then it must be true that...

With the development of industry, the proletariat not only increases in number but also becomes concentrated in greater masses and feels its strength more