London, April 3, 1872
Citizens,
The General Council of the International Working Men’s
Association has asked me to congratulate you on its behalf
on the occasion of the second congress of the Spanish sections. You are indeed to be congratulated for the results
you have obtained in so short a time. The International,
founded in Spain less than three years ago, now covers the
whole country with its sections and federations, is established in all the towns and is penetrating into the countryside. Thanks to your efforts, and also to the senseless and
ridiculous persecution by successive governments of your
country, you have obtained these fine results and made
the International a real force in Spain. We ought not to
forget, at the same time, that these results are also due to
the special constitution of our Association which leaves
every national or local federation complete freedom of
action, granting the central organs only such powers as
are absolutely essential to enable them to safeguard the
unity of the programme and common interests, and to
prevent the Association from becoming a plaything of bourgeois and police intrigues.*

You have probably still to come in for further persecutions. Remember then that there are other countries, like
France, Germany and Austria-Hungary, where the members
of the International suffer even harsher government
repression and yet do not bow their heads, knowing, as you
know, that persecution is the best means of propaganda
for our Association, and that there is no force in the world
strong enough to suppress the ever-growing revolutionary
movement of the modern proletariat. In order to destroy
the International it would be necessary to destroy the soil
of which it is the natural product: modern society itself.
Greetings and fraternity,
On behalf of the General Council,
Secretary for Spain,
FREDERICK  ENGELS
No. 44, April 13, 1872;
May 4, 1872