The Twenty-one Conditions, officially the Conditions of Admission to the Communist International, refer to the conditions, most of which were suggested by Vladimir Lenin, to the adhesion of the socialist parties to the Third International (Comintern) created in 1919. The conditions were formally adopted by the Second Congress of the Comintern in 1920. The conditions were:
The periodical and other press and all the party’s publishing institutions must be subordinated to the party leadership, regardless of whether, at any given moment, the party as a whole is legal or illegal. The publishing houses must not be allowed to abuse their independence and pursue policies that do not entirely correspond to the policies of the party.
In the columns of the press, at public meetings, in the trades unions, in the co-operatives – wherever the members of the Communist International can gain admittance – it is necessary to brand not only the bourgeoisie but also its helpers, the reformists of every shade, systematically and pitilessly.
The Communist International unconditionally and categorically demands the carrying out of this break in the shortest possible time. The Communist International cannot tolerate a situation where notorious opportunists, as represented by Turati, Modigliani, Kautsky, Hilferding, Hillquit, Longuet, MacDonald, etc., have the right to pass as members of the Communist International. This could only lead to the Communist International becoming something very similar to the wreck of the Second International.
As a rule the programme of every party belonging to the Communist International must be ratified by a regular Congress of the Communist International or by the Executive Committee. Should the Executive Committee of the Communist International reject a party’s programme, the party in question has the right of appeal to the Congress of the Communist International.
During the December 1920 Tours Congress of the French Section of the Workers' International (SFIO), the 21 conditions were rejected although the majority, led by Fernand Loriot, Boris Souvarine, Marcel Cachin, and Ludovic Frossard, adhered to the Third International, creating the French Section of the Communist International (SFIC), which would later take the name of the French Communist Party (PCF).