He devoted much effort to fighting the nationalist unions that supported the war, along with Alphonse Merrheim, Albert Bourderon and Raymond Péricat.
Fernand Léger | Fernand Khnopff | Fernand Braudel | Fernand Petzl | Fernand Lamaze | Fernand Pouillon | Fernand Loriot | Fernand Leduc | Fernand de Brinon | Loriot | Fernand St. Germain | Fernand Sardou | Fernand Point | Fernand Petiot | Fernand Mourlot | Fernand Meyssonnier | Fernand Lungren | Fernand Lafontaine | Fernand Holweck | Fernand Guyou | Fernand Goyvaerts | Fernand Demets | Fernand Dansereau | Fernand Crommelynck | Fernand Collin | Fernand Charron | Fernand Braudel Center | Fernand Auwera | Fernand Auberjonois |
On 15 August 1915 a pacifist resolution was presented at the CGT's national congress at the initiative of Alphonse Merrheim and Albert Bourderon, signed by several militants of the federation of teacher's unions including Bouet, Fernand Loriot, Louis Lafosse, Marie Guillot, Marie Mayoux, Marthe Bigot and Hélène Brion.
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).